Chapter Text
A horn sounds, bright and clear, and Izuku twitches back the curtain on his window despite the chill waiting to creep in.
There is a flurry of men and animals scattering across the courtyard as the gate begins its slow descent down across the moat. Soon, every one of them will be Izuku’s responsibility, and despite the months he’s had to acclimate himself to that fact, his stomach still lurches in terror at the prospect.
One for All flows smooth and sure underneath his skin, the power rippling at his fingertips and everything he’s ever wanted. But how King Yagi thought Izuku was the one who should inherit it, become king, is beyond his comprehension.
How in the name of all the gods high and low is Izuku supposed to rule anyone? Magicless, penniless, from a tiny village clinging to the edge of a mountain in the far north of the kingdom, and somehow he is Yagi’s chosen successor.
It’s mad. He’s pretty sure at least half the court thinks that as well. More than half, even.
The small cadre of knights who’ve been stationed at the capital through the autumn line up outside as the procession of those who’ve been off driving back the wyvern horde at their eastern flank begin to tramp their way on horseback across the drawbridge for Izuku’s investiture as the crown prince. Most Izuku only knows by reputation and crest, long hours spent hunched over endless tomes filled with history and lineages, all the minutiae of a kingdom Izuku feels desperately ill-equipped to lead with his bumbling manners and inveterate earnestness, no matter how many times Uraraka drills him on proper etiquette.
Yagi seems unfazed by it all, more than sure of his decision, and every day Izuku’s magic grows, an enormous well of potential that makes it worth it. Probably. Maybe.
If the elder Todoroki doesn’t murder him in his sleep, still apoplectic about his family being skipped over for the succession, again.
More and more banners fill the courtyard, a stomach churning sight as they all assemble before him for the first time. And there, at the back, an explosion of blond hair and sure posture, whom Izuku would recognize anywhere, no matter how clearly he’s grown over the better part of the decade since Izuku last saw him. Even from afar, Izuku can imagine the stormy expression on his face as he trails behind Hakamada and Kamihara, their oak leaf and chrysanthemum crests both snapping in the wind, and he drops the curtain with a lurch.
“Kacchan,” he whispers into the silence of his bedroom, judgmental tapestries his only witness, while his heart thumps erratically in his chest.
*
“Izuku, come, come!” Yagi calls through an antechamber doorway, and Izuku changes direction, nearly catching himself on his new long robes in his haste. Of course all his clothing now is of a quality he never could have dreamed of in his childhood, but no one prepared him for just how intricate and damnable the trappings of royalty actually are.
“Can I help—” Izuku pulls up short at the sudden reappearance of Katsuki in front of him, like a strange mirage, the same and overwhelmingly different, with Izuku wholly unprepared for this moment to happen quite so soon. He thought he had hours yet.
Katsuki has filled out handsomely, no longer the gangly teenager Izuku remembers, broad shouldered and exuding a strength that can only come from years of constant dedication to the sword. His armor gleams, the large head of a wolf serving as his right pauldron, as fierce and intimidating as the man himself, and his sword glows with a smattering of rubies, magic pulsating within them. A trim waist and the straight back of a soldier, a knight of the highest caliber, but with that subtle touch of insouciance that only Katsuki could still have after all these years of training, and a sharp wrench of childhood nostalgia nearly takes Izuku’s breath away.
But Izuku has grown as well and they are nearly of a height now as he meets the banked fire of Katsuki’s gaze head on, dark, steady, a vastness of time passed and careful calculation of where they both remain, and he forgets entirely that Yagi is speaking. There’s a scar now across Katsuki’s cheekbone, jagged and already fading faintly into the white of his skin, while the barely contained spike of his hair spills across his forehead, his boyish looks still there and yet also grown into the most assured presence of a man.
The third man in the room, whom Izuku has never seen before and hadn’t even spared a glance to notice, snaps into a deep, full bow all at once, finally wresting Izuku’s attention away.
“Todoroki Shouto, at your eternal service, Crown Prince Midoriya,” he says without equivocation or malice.
Ah, the Todoroki heir, then, that Yagi has famously skipped over. At least they’re off to a better start?
“Thank you.” Izuku gives a short bow of his own, as Yagi beams next to them.
Katsuki merely inclines his head in a bow that is respectful but almost certainly far too casual for such a situation, and Izuku has never been more thankful for his stubborn insistence on being himself. If he ever treated Izuku with such total deference, Izuku might have to fling himself from the castle walls.
“Kacchan,” Izuku whispers, forgetting himself and their company, as his eyes mist up at the mere prospect of having an old friend from that same tiny village here, in this place, while everything changes irrevocably, no matter how fraught that friendship may have been left so many years ago.
“You two have already met?” Yagi inquires, startling Izuku into attention once again as he finds two sets of inquisitive eyes watching their interaction, one with something like surprised glee.
Izuku gulps and stutters, “Well— Yes, you see—”
"We're from the same village,” Katsuki interrupts, voice gone deeper and smoother with age, and Izuku shivers as Yagi claps his hands together in excitement.
"How wonderful! Izuku, you should have mentioned you grew up with one of our most promising knights! Yes, yes, just perfect actually. Izuku needs a personal guard and you're the perfect candidate. Perfect!”
Katsuki snaps his neck so hard, eyes finally leaving Izuku's for the first time since he entered the room, that it's a wonder it stays attached at all. Izuku isn't sure what face he's making, mouth agape and no sound able to form, but he imagines it conveys the same intelligence as the fish they had for dinner the night before.
“Excuse me?” Katsuki’s voice goes so shrill and high that if Izuku weren’t so gobsmacked himself he would laugh.
Izuku squeaks and then chokes, no actual words forming to prevent this impending disaster.
Kacchan, his personal guard?! Oh gods…
He was hoping to keep their interactions light and positive, give Katsuki time to adjust and perhaps eventually overcome whatever shadows of their childhood still remain. They were close once after all. Izuku would love to repair their friendship, but forcing Katsuki to follow him everywhere, interact constantly is too much. It’ll surely send Katsuki up a wall having to defer to Izuku of all people every second of every day. He can only imagine what Katsuki must have thought when he heard who was chosen as Yagi’s successor.
Todoroki cuts in, “What a great honor for you, Bakugou,” but with his utter deadpan delivery Izuku can’t tell if he believes it is an honor or not. Is it an honor? A demotion? How would Izuku know!
When Katsuki looks like he might bite Todoroki’s face off, Yagi continues, “A great honor! I really must visit this village someday that produces such fine, strapping young men.”
Izuku sometimes wonders if he’s intentionally this oblivious or has become so after so many years of being king.
With a clear grind of his teeth, Katsuki straightens up and dips his head down. “Thank you, King Yagi,” he grits out.
“Splendid! I have some other matters to attend to for the ceremony tomorrow, so I will leave you to figure out the logistics for now. There’s a room for you to take over on the same floor as the Crown Prince’s now that that’s decided.” Yagi beams, thoroughly pleased, and is gone before Izuku can move a muscle or lodge a protest of his own.
Izuku smiles and laughs, awkward and stretched thin, while Katsuki glowers fully now that the King is no longer within sight.
“Bakugou never mentioned your acquaintance either,” Todoroki muses, voice dry but mismatched eyes intent on them both.
“Fuck off, Icy Hot,” Katsuki growls without sparing him a glance.
Todoroki huffs and then bows towards Izuku. “It was a pleasure to make your acquaintance, Crown Prince. I look forward to working with you and serving as your knight.”
“It is my pleasure, Todoroki.”
“Please call me Shouto. My father can have the Todoroki name.”
Well that is a loaded statement if he has ever heard one. Izuku isn’t going to touch whatever is happening in that family with a ten-foot pole.
With an incline of his own head, Izuku laughs good naturedly and pretends that’s a perfectly normal thing to say about one’s father, one of the most famous knights the kingdom has ever produced. Having met the man, Izuku thinks he can understand why. “Shouto then.”
“I’ll leave you to it,” Shouto says, dry as ever, and excuses himself with a heavy glance.
On second thought, Izuku would rather delve deeply into the psyche of the Todoroki family with Shouto than be stuck here, with Katsuki’s loaded, molten gaze.
Wringing his hands, Izuku tries to pull a smile back onto his face, but knows he must be missing the mark by a wide margin. “Hi, Kacchan.”
With a dramatic groan, Katsuki tosses his head back and then turns.
“Let’s get this over with.” When Izuku doesn’t immediately trail after him, he yells without turning, “C’mon, Deku!”
Izuku has never been more glad to hear that stupid nickname and he trips over his robe with a grin on his face as he chases after Katsuki.
*
Izuku awakens bit by bit, awareness blearily making itself known until he jolts upright all at once.
Today is the day. Afterwards his position in the kingdom will be set, his name proclaimed from the smallest nook and cranny of their domain. Today makes it all expressly, undeniably real.
Glancing behind his curtains, he’s surprised he was able to sleep this late, although truly not late at all. He hasn’t heard a peep from anyone all morning, when he has had all manner of people vying to take care of him, instruct him, insist he do things now every morning since he was announced.
Some tea would be nice about now though, he mutters to himself as he pokes his head out into the corridor and is rapidly confronted with the reason for his quiet morning: Katsuki’s implacable presence outside his door, arms crossed and formidable scowl apparent. His hair has gone flat, spikes drooping, and there are bruises under his eyes, speaking to a long night upright.
Katsuki glances over and says with great exasperation and sarcasm, “Glad to see you finally moving, Your Highness.”
“I think you’ve scared away everyone who might’ve woken me,” Izuku murmurs, laden with humor as he catches sight of the servants huddling at the other end of the corridor, clearly still too terrified of Katsuki to approach but relieved to see Izuku awake at last.
Katsuki scoffs. “So used to having servants now you can’t take care of yourself in the morning?”
Izuku laughs softly, still blinking sleep away in the quiet morning air, warm and content with Katsuki’s familiar belligerence in his life again. Katsuki twitches and then turns back to the corridor, scowl firmly back in place.
“You should have slept. Today’s going to be a long day,” he whispers as he waves for his breakfast.
“Today is by far the most dangerous day. You haven’t inherited your full powers yet and with the influx of people gathered here for your investiture it would be the perfect opportunity for someone to attack and get away during all the chaos. I’ll sleep later.”
Heart lurching, Izuku says, warmth overflowing in his voice, “Thank you, Kacchan.”
Katsuki tsks. “Don’t thank me for doing my job. If the King wants me to protect your ridiculous ass, then that’s what I’m going to do. Idiot.”
It probably says something about him that all he can do at Katsuki’s brash insults is laugh, loud and full. It’s nicer than deference any day.
*
Having Katsuki shadow his every move is like being trailed by a particularly hostile, ornery ghost who’s determined to scare off anyone who might approach through sheer aura alone. The other knights are unbothered, long used to his presence, but Izuku’s not sure he can complain about how the courtiers scatter in Katsuki’s wake, even if he should. Today is nerve wracking enough as it stands.
When Yagi had given Katsuki this assignment yesterday, Izuku was certain Katsuki would be pushed too far, the shock of having to report to, to be ruled by someone he once thought so little of an insurmountable obstacle. As a child Izuku had been determined to prove his worth to Katsuki one day, to see them both on equal ground. This is so far beyond that as to be laughable.
But Katsuki has said little overall since the previous evening, performing his duties with a glower to match no other, haunting Izuku endlessly day and night after doing little more than storing his own belongings. And yet despite his gruff demeanor, there’s been no true bite to his bark thus far.
It’s more grounding than Izuku could have expected.
No amount of grounding can prepare Izuku for this though, stood in front of the doors to the great hall, in many layered stiff robes that had taken two hours and too many servants to fit him into, scrubbed and anointed and entirely too foreign for Izuku’s simple tastes.
As Izuku’s constant twitching and hand wringing grows more agitated, he can sense the end of Katsuki’s patience quickly approaching.
“Stop fidgeting, Deku,” Katsuki growls.
“Sorry, sorry!” Izuku says with a wince, and attempts to still his body. When that does nothing but cause his heartbeat to overflow, ears ringing hollow, he throws his hands up. “Oh gods, what if this is all a mistake, Kacchan! Who in their right mind would entrust me with an entire kingdom— this is madness.”
Katsuki groans and heaves an enormous sigh, head thumping back against the cold stone wall, before turning towards Izuku, fire in his crimson eyes. “Look at me, I’m only going to say this once. You may be an idiot with less sense than a titmouse in order to have gotten yourself into this position in the first place, but Yagi could have done much worse. I’ve seen the snakes vying for his attention. He made his choice.”
Tears well thoroughly and immediately in Izuku’s vision, blurring the outline of Katsuki's sharp cheekbones and the intensity of his burning eyes that could flay the skin from Izuku’s bones.
“I think that's the nicest thing you've ever said to me," Izuku whispers, choking down a sob.
“Fuck off," Katsuki hisses as if a grave mortal offence has been committed, the audacity of someone claiming anything he's done as nice.
Izuku beams, watery eyes and sniffles and all, and thinks that maybe he can do this. At least with someone like Katsuki at his side.
When the doors open, exposing the great hall in all its glory, the light through the stained glass bathing everything it touches in a soft kaleidoscope of infinite color, Izuku can take a deep breath and straighten his back, striding in with his head held high like the heir he is meant to be. Katsuki follows in the shadows, his presence a steady pulse in his periphery, and for the first time Izuku can meet Yagi’s proud, glowing face with a twinkle of his own.
As he kneels before Yagi, prostrate and solemn, he allows himself to believe maybe it will all be okay.
Then Yagi touches his head and One for All flares beneath his ribs, obliterating any thought at all such that Izuku is almost unaware of the great thunder strike of green lightning that spears through him and in him, sending everyone cowering back and covering their eyes as the ground shakes beneath their feet.
*
The celebration continues long into the night, the hall transformed into endless tables laden with more food and drink than Izuku has ever seen. Passed from dignitary to knight to librarian, Izuku swirls among the people — his people now — and takes toast after toast, until the alcohol flows like syrup through his veins, tinting the night in a pleasant, effervescent glow.
When he finally sneaks off to collapse into the wall at the edge of the room next to Katsuki, Katsuki's lip curls. “You reek. How much have you had to drink?"
"Not that much, I swear,” Izuku giggles.
Katsuki scoffs. “Liar. I’ve been watching you all night.”
“Have you?” Izuku wonders, interest thoroughly piqued, and then lurches into Katsuki’s chest when he attempts to lean closer in his exuberance.
“For fuck’s— I’m your guard, idiot,” he growls, pushing Izuku back upright, and then seems to come to a decision. “That’s it, time for bed.”
With a scruff of Izuku’s neck, he frog marches Izuku out into the corridor and up towards his personal chambers, utterly unmoved by Izuku’s pouting and lack of cooperation. “It’s my celebration, Kacchan!”
“And those assholes are all three sheets to the wind, much like you. No one will even notice.”
When Izuku trips over the stairs for the third time, Katsuki curses and hoists Izuku over his shoulder like a sack of rice.
“Kacchan!” Izuku screeches, glad no one is around to see their prince in such indignity, and also strangely thrilled. This is new. Katsuki's shoulder is firm and thick under Izuku's chest.
“Gods, when did you get so heavy, you’re built like a mule.”
Izuku thumps his fist into Katsuki’s back. “You take that back!”
With a grunt, Katsuki shoulders the door to his room open and drops Izuku onto his bed without ceremony. “I hope your hangover is vicious tomorrow."
"So mean,” Izuku whines.
"Shitty Hair is guarding your door tonight instead of celebrating, which is his punishment for poking at things that aren't his business.”
Shitty Hair? Izuku thinks blearily.
"If you even remember this conversation tomorrow.” With a kick to Izuku's bedding, he orders, “Sleep.”
But the room is so warm and the light filling Izuku's chest is so comforting that he's already gone.
***
The kudzu flows around a rocky outcrop and Izuku follows it into a glen he’s never seen before: deep, damp, careening down into green warmth around a gently burbling stream. Flowers explode up and down the sides of the valley, a jagged rend in the earth clawed out by time and now forgotten.
It’s perfect.
Izuku eyes up the bellflower and hagi, imagines what potions and salves he can learn with the thoroughwort clinging to the banks of the brook, and pulls his knife out and prepares for an enjoyable afternoon of rooting around in the mud.
As the sun makes its turn around the sky, his awareness stretches and snaps up at something new on the other end of the glen. A pure white horse with a gleaming, silver mane stands across from him, and as she turns to face him properly he sees the horn, glinting in the late day sun like a beacon, and he whispers in stunned awe, “A unicorn.”
They stay in placid observation for countless minutes until Izuku bows his head from his perch on his knees by a towering dianthus, its pink petals fluttering down in the wind and along his neck. With a dip of her own head she slowly trots off again in radiant splendor and Izuku is left shaken by the ancient immensity of her being.
Spell broken, he tears out of the glen, plants long forgotten as he mutters to every creature between him and the village about his plans to ransack the library in the nearby town for every speck of knowledge he can glean about unicorns.
*
Izuku goes back day after day, longing for just one more glimpse, while his master tuts about his overactive imagination. “If you want to learn to use the magic of an apothecary, concentrate on your plants and studies!”
But Izuku doesn’t only want to be an apothecary, not truly, merely hopes that somewhere in the herbs and muck he’ll be able to divine some inspiration for magical talent where none has been before. That unicorn is the most pure magic he has ever encountered and the urge to reach out and touch it again drives him on.
*
She comes back, on cautious, nimble hooves, grazing on golden lace and mugwort, bright yellow buds clinging to her forelock. The glen is rich and while she keeps her distance, she still comes.
Izuku scribbles with renewed furor, the paper nearly unable to contain the sheer volume of his note taking. As the days pass, she ventures closer to his rocky perch above the stream, and he begins to whisper to her.
“Where’s your home?”
“Are you alone? Are you the only one of your kind?”
And, “What should I call you?”
She has no answers, but the wisdom of her eyes as she holds his own speaks of a deeper understanding.
“I think I’ll call you Eri. I’ve always liked that name.”
She merely nickers in quiet acquiescence and moves on to the spicebush berries near his feet.
*
Sometimes he sings.
He doesn’t have words for the effervescent joy bubbling out of him as she begins to lie by his feet and sleep off her feast, only the tremulous notes of whatever songs he can conjure, carried away on the breeze. With supreme gentleness he pets her side and brushes back her mane while he hums.
If he never becomes a knight, can never conjure a spell of his own, he thinks in these moments that he could be content anyway. The magic flows so strongly even he can feel it, from sunbeams to blades of grass and the slip of water over smooth stone.
*
He should have expected that the peace and solitude would shatter, the gentle warmth of the glen rippling with otherworldly energy gone dull and cold.
The hunters, whom Izuku doesn’t recognize, unsheathe iron and cock bows, hissing about evil omens, and Izuku flings himself in front of Eri, hands splayed wide in supplication.
“Please stop! She won’t hurt you, she’s just a unicorn,” Izuku begs, and wishes for the first time in weeks for a sword of his own.
The leader, a wizened old man with a terrible sneer, spits at the ground. “Move, boy. Or we’ll gut you too. We won’t have these woods so close to our homes contaminated with the likes of demons, lest they call the Demon Lord to our doorstep again.”
The protest dies in Izuku’s throat as he feels Eri rear back behind him with a great and terrible bray that splits his eardrums and sends the hunters scattering. As he turns to calm her, fingers dancing along her neck and words soft on his tongue, an arrow pierces his shoulder right in front of her heart. Her screams reach a pitch that pushes him straight to his knees and the hunters flee into the wind.
But they’ll be back, in stronger numbers, of that he has no doubt.
*
Izuku feels the hot glide of tears down his face and salt on his lips as he murmurs into Eri’s neck, “You need to leave now, Eri. And you can’t come back. They’ll kill you if they ever find you here again.”
She nibbles at the tears on his cheek, eyes dark with sorrow, then rests her head against his own.
There are no words, and yet deep within his breastbone her meaning rings like a bell: Thank you, young one, my aid is always yours. We will meet again someday.
Overcome with sobs he watches her gallop off into the distance, a gleaming white visage that still shakes him to his core with awe.
“You know, they say only the truly pure of heart can speak with unicorns,” a gentle voice says behind him.
Izuku trips over his own feet and is viscerally reminded that he still has an arrow lodged in his back and needs to escape this place himself. Before he can fall, an older man, broad shouldered with kind blue eyes, grasps him with firm hands and deposits him back on his feet, careful of his injured shoulder.
“Whoa there, young man. I think you’ve taken enough damage for one day.”
Izuku stutters, “I’m so sorry, you startled me, but we really must leave before the hunters come back—”
The stranger laughs with a deep boom, completely unbothered, and Izuku notices the quality of his clothing, the cleanliness of his blond hair and sparkling teeth. “Our wise friend’s magic called out to me and brought me here at once. But I see she already had her own protector. You saved our kingdom from a grave curse today.”
He gives Izuku a once over and his grin widens. “So how would you like to learn real magic?”
As Izuku finds the sigil on his cape and the gold signet rings on his fingers it all clicks together in one shocking, life-changing second, and he falls to his knees, head bowed to the ground. “King Yagi,” he blurts, then glances up as he continues, “Y-yes. Please… Sire.”
King Yagi rubs his hands together with glee and claps Izuku once on his good shoulder, hard, nearly sending his face flying into the dirt. “Let’s get you to the healer first and get you all cleaned up and ready to begin training.”
“Tr— Training?”
***
As autumn turns to winter and the harvests are brought in, Izuku’s new life begins to settle into something steady, predictable. With the full transfer of power One for All blossoms anew under Izuku’s hands, a perpetual thrum ready to be set loose in an instant, and under constant training in front of Yagi’s watchful eye. There are endless meetings, the minutiae of the kingdom keeping him up late into the night as he feverishly attempts to learn everything he can under flickering candlelight. And there is Kacchan, his eternal, glowering shadow.
After a few weeks as the official crown prince, Izuku can see the spread of days before him beginning to take shape, the outline of his life drawn.
Which is when Katsuki strides into his room, unannounced as always, and throws a sword at Izuku’s feet while Izuku is mid sip of his tea, blinking at the sudden, early intrusion. The sword rings between them in a bright arc of morning light.
“I’ve been instructed to improve your swordsmanship,” he challenges.
And that is apparently that.
*
The sword Katsuki threw at his feet was a lie, Izuku thinks, sweat dripping down his neck and under his collar, while his body steams in the brisk air of near winter.
No, Katsuki had no intention of letting him touch a sword, luring him in with false promises and then handing him a stick and having him play swords with it, like a child.
“It’s not a stick, it’s a practice sword. And stop muttering!” Katsuki says with great exasperation.
“I’ve had sword training before, you know,” Izuku huffs.
“I’ll be the judge of that. I can see your form, who trained you, the apothecary?”
When Izuku crosses his arms and tries not to pout, Katsuki barks a laugh so loud birds go flying into the sky and Izuku resists the urge to stamp his foot. Only Katsuki could make him all of five years old again, still tottering after his favorite person. Yagi would probably belly laugh and slap him on the shoulder, saying it’s good for him. He’s been utterly delighted by how impertinent Katsuki is towards Izuku.
But at the moment Izuku is remembering vividly how infuriating Katsuki can be sometimes.
“Yagi trained me with a sword!” As well remains unsaid. His apprenticeship as an apothecary was good for many things, combat not one of them, and he’d had no sword of his own.
While the glint of humor remains in Katsuki’s eyes, he sobers enough to say, “He’s trained you to use magic, with a sword and without. There's much more to true swordsmanship than that, and if you’re to fight the Demon Lord you’ll need both.”
Izuku softens under the sheer truth of that statement. As the days grow shorter and All for One remains unseen the court grows more nervous yet. He studies the wood in his hand, the feeling of the smooth grain of the hilt under his fingers, with a nod.
Whatever the great dragon has planned, Izuku will need every advantage he can muster. Yoichi shaped the power that flows through his veins and founded this kingdom to protect the people from the Demon Lord and that is now Izuku’s burden to bear.
Across the training field, Kirishima and Kaminari spar, the sound of their swords echoing in the courtyard. Izuku watches them for a moment, the great clamor of their blades and magic clashing against one another, and nods once more, gripping his training sword more firmly as he says, “Alright, show me again.”
*
“Lower,” Katsuki barks and kicks at Izuku’s back foot until he has no choice but to deepen his crouch, thighs burning under days of Katsuki’s exacting tutelage.
Gods, why did Yagi have to choose Katsuki for this task? Surely someone else has the time… but even as he begins to think it, Izuku knows he wouldn’t want to be learning from anyone else, no matter how demanding a teacher Katsuki is or how thin his patience can be.
Apparently still dissatisfied, Katsuki moves behind Izuku and molds himself to Izuku's back, gripping Izuku's hands within his own and forcing him lower still.
“Like this," he murmurs straight into Izuku's ear, while guiding him through the movement, smooth and sure, stance shifting as the training sword arcs in their grasp.
Izuku can feel the buttons of Katsuki's shirt through his own, the ridges of his belt buckle and sheath of his sword. Like this, the exact breadth of his shoulders is obvious, as wide as Izuku’s own, but the whip-thin strength of his hips is also apparent, a stunning contrast to Izuku's densely muscled thighs, and through it all an inferno of heat, like the fire raging inside Katsuki is too much for his body to contain. The sudden shock of it flashes through him hot and cold at the same time, breath deserting him all at once.
Katsuki comes back around, eyes discerning with concentration, and says, "Again,” while Izuku merely blinks at him, thoughts scattered to the wind. “Deku!"
Izuku shakes his head, flush blooming up his neck, and forces himself back to the beginning of the stance.
“Shouldn't you show more respect to your prince?" he mutters sidelong and Katsuki scoffs.
"Absolutely not. Now get moving.”
And somehow, despite Izuku's mind fleeing him, he goes through the motion and can feel the difference now, how the sword moves surely, cutting through the air in a way that is right, and he can't help but grin at Katsuki in triumph.
Despite his eye roll, even Izuku can see the upward twitch of Katsuki's lips. "Don't get cocky,” he grumbles with no heat. “Idiot."
*
Most days they take lunch together now, before Izuku is absorbed in the infinite other duties before him.
The silence is…companionable, more than Izuku would have expected. If anything, Katsuki has grown more quiet with age, a hundred thoughts flowing in the intensity of his eyes, his expressive face speaking for itself when words do not.
As Izuku chews his fish thoughtfully, he studies the sharp jut of Katsuki's cheekbones, the deep red of his downturned eyes lost in contemplation. Katsuki shoves another mouthful of rice into his mouth and then scowls when he realizes Izuku's attention is focused on him.
“What?" he snaps.
Izuku looks down at his bowl with a small smile. “This is nice, is all. Training and eating together, being… around each other again. I missed it when you left,” he says, voice soft, then sniffles a bit because it’s true. Despite everything, he had missed Katsuki dearly, and having this time together now is a gift. Then he has to rub at his eyes before he begins crying in earnest.
"Still a damn crybaby, aren't you,” Katsuki scoffs, but it almost sounds fond to Izuku’s ears, or as close to fond as Katsuki’s voice is probably capable of.
Izuku also notices that Katsuki didn’t deny that it’s nice and laughs while wiping at his cheeks. “Never could have imagined that we’d meet again like this though, with you as my guard. Or me as a prince. Maybe could have imagined that you’d be the one trying to murder me instead,” he teases.
Katsuki narrows his eyes dangerously. "If anyone is going to murder your sorry ass, it'll be me,” he hisses.
"Okay, Kacchan,” Izuku responds with a wide grin that crinkles his teary eyes.
*
When Katsuki deems that Izuku is “no longer a danger to others,” they begin to join the other knights for training, which is how Izuku finds himself across from the giant red-haired mountain of a man that is Kirishima Eiijirou, who is just as immovable as he looks.
Gods, is he made of granite? Izuku wonders yet again as their swords clash together, taking all of Izuku’s strength to absorb the shock up and down his arms. He manages to hold Kirishima back and then push his sword to the side, hilts still locked while Izuku steps in and uses his lower center of mass to duck under and catch Kirishima’s feet with his own, sending him back.
Kirishima doesn’t fall, but for the first time he wobbles, just slightly, and steps away to regain his balance, sword falling by the wayside.
Finally.
Kaminari and Sero cheer and jeer at Kirishima good naturedly, while Izuku pants and allows himself to rest. Izuku is by no means a small man, and training as Yagi’s personal oxen for months did him wonders, but Kirishima is truly something else, especially when they’re sparring without the use of magic.
“Good round, Your Highness,” Kirishima says with a huge grin, not unlike a puppy who can’t imagine anything better than playing with his friends.
Izuku can’t help but note that Kirishima’s breathing is hardly elevated at all and laughs. “The pleasure is all mine. You must be quite the rock out on the battlefield.”
“You have no idea,” Kaminari cuts in, cackling. “Once we were defending a village that had somehow angered a neighboring faerie mound—”
“Don’t you dare,” Katsuki hisses to no avail.
“—and they managed to hurl a boulder at Bakugou, flattening him like a hotcake against Kirishima, who barely felt a thing. Never seen Bakugou just fall over like that — even his hair went flat!”
While the rest of the knights howl with laughter at the memory, Katsuki spits, “I should have killed those little faerie fucks!” which does nothing in the slightest to calm their amusement.
“Somehow Kacchan has failed to mention that misadventure,” Izuku says with a sly grin at Katsuki, who has worked himself into a true froth by this point.
“You should have dinner with us, Your Highness, we have plenty more stories about Bakugou where that came from,” Kirishima adds, while Sero and Kaminari bounce in excited agreement.
“I knew this was a terrible idea, you’re all traitors!” Katsuki bellows.
While Izuku pats Katsuki on the back consolingly, he hears Sero whisper, “Kacchan?” which only sets Katsuki off once again.
*
Of all the inconceivable things now in his life, Izuku doesn’t think he will ever grow used to the crown. The sheer weight of it, both real and metaphorical, is enormous, and it shifts the entire way he carries his body, his whole demeanor, the way others defer and react to him, everything.
It makes it all real in a way almost nothing else does.
Izuku shifts forward to concentrate on the maps before them and has to angle his head back slightly lest the crown fall.
“We’ve sent patrols out all along the border, even deep into the mountains up north here,” Hakamata says while tracing along a path not far from Izuku’s childhood village. “There’s been no sign of the Demon Lord at all. Nothing.”
“It’s too quiet,” Todoroki growls, his enormous presence still a menacing shock to Izuku, and Izuku can’t disagree. He stares straight at Izuku as he continues, “He’s planning something. He knows how weak we are right now, I’m only surprised he’s waited this long for whatever it is.”
It takes everything in Izuku to meet that dismissiveness head on and not wilt under the scrutiny, because he’s not wrong; One for All may pulse through Izuku’s veins, but true skill can only be bought with time, of which who knows how precious little they have.
At his side he can feel Katsuki step up with a snarl on his face, Katsuki whose presence has already raised a few eyebrows when Izuku very well could have left him outside the meeting hall, but Yagi intervenes with a placating arm raise before Katsuki can do something insane like yell at the commander himself. Izuku ignores the pleased flush that Katsuki’s protectiveness raises up the back of his neck.
“And all we can do is prepare and be ready for when that occurs, like always,” Yagi says, smile not reaching his eyes for once. “One for All will be safe in Prince Izuku’s hands.”
Izuku bows his head, somber, as he says, “I will be ready to serve the kingdom to the utmost of my abilities.”
“Of course you will, my boy.” Even with his head bowed, the warmth in Yagi’s voice is apparent, the smile almost certainly radiating once again.
“He better be. I leave for the border tonight to oversee continuing preparations,” Todoroki sneers, and then dismisses himself, heading for the exit. Just as he passes Izuku and Katsuki and opens the door, he adds, voice low, “Control your attack dog.”
Hakamata moves to follow, with a mild, “Bakugou,” in rebuke on his way out, and Katsuki actually bows his head in apology to him. Katsuki has said little about his years training and then fighting under Hakamata, but Izuku can’t help but implicitly trust the man who has earned Katsuki’s respect and unfailing loyalty.
Shouto is waiting benignly just outside the door with a raised eyebrow as he watches his father storm down the hallway. “Please feel free to challenge him next time, Bakugou. I would enjoy watching that.”
“Don’t give him any ideas!” Izuku pleads, but judging by the glee in Katsuki’s eyes it’s far too late for that.
*
When their swords go clattering to the ground, Izuku continues forward with grappling hands, unwilling to give Katsuki even an inch of ground on him, which he knows Katsuki would have no qualms about using to his advantage. He's ended up on his back more times than he cares for and it is high time he gives Katsuki a taste of his own medicine.
Katsuki may have the slightest edge in height and many more years of training, but Izuku has bulk and the strength of the kingdom flowing through his veins now and he's learning how to use it.
As he pushes at Katsuki, they end up entangled, legs wrapped around each other and chest to chest, their light training armor doing little to hide the feel of their braced thighs and panting breaths. It's exhilarating in ways Izuku isn't able to comprehend, with no time to process as they both hurtle to the ground, still shoving at each other to gain the upper hand. Eventually Katsuki manages to pin one of Izuku's forearms to the dirt and shove his legs apart, but before Katsuki can fully grapple him down, Izuku thrusts up with a growl into Katsuki's neck and uses his thighs to wrap around Katsuki’s waist and flip them over completely.
Izuku laughs with glee from his new perch atop Katsuki's thighs, while Katsuki gapes up at him, pink cheeked and frozen stock-still in surprise, eyes wider than Izuku's ever seen them.
"I win," Izuku chirps.
Katsuki chokes and then dumps Izuku into the dust, pulling himself backwards until he's leaning against the courtyard wall, legs spooled out in front of him as he bangs his head against the stone with a groan.
When he opens his eyes, he stares Izuku down, piercing and unfathomable, but merely says, "You're improving."
"Only because I have such a good teacher," Izuku can't help but tease.
Katsuki rolls his eyes, the intensity reverberating between them finally deflating. "Suck up."
*
“Come in, my boy, come in!” Yagi waves him in, but Izuku’s attention is caught short on the gleaming armor laid out in the room, each brace and greave polished so highly that the light streaming in through the window refracts over every bright facet such that it seems to glow on the table, otherworldly and untouchable.
“What’s… all this?” Izuku wonders, hushed, and reaches a hand out, but stops short, afraid to touch.
Yagi laughs. “Your armor, of course! While we’ve made do thus far with the more every day pieces, the armorer has been at work for months on this set. You are the crown prince now, after all.”
Swallowing, Izuku closes the gap with hesitant fingers and admires the warmth of the metal, how it feels almost alive under his touch. He can see runes hidden in the intricate designs of leafy branches twinned together around the edges, the shimmery outline of a unicorn carved faintly across the breast. For an object to already be filled with so much power… Something like this should take years to imbue, slowly growing as magic is layered within it over time.
“It's stunning," Izuku chokes out, utterly overwhelmed and on the verge of tears.
"I wanted it to be a surprise. But all of our strongest knights and sorcerers have been down to the armory helping to weld our best protection spells into each piece.”
Tears falling, Izuku whispers reverently, “I can tell. I've never felt anything like it.”
“And it will only grow stronger as you weave your own magic into it! A true extension of yourself, much like my armor has served me over the years.”
Izuku looks up into Yagi’s beaming face, grin wide and unfettered and laugh lines crinkling at the corners of his eyes, and has never felt more grateful to someone in his life.
As a child he never could have imagined a fraction of any of this.
“Thank you,” he says with the full force of his emotion.
Yagi begins to tear up himself as he takes Izuku’s hands. “No, thank you, Izuku. I know thrusting this responsibility upon you is a lot to ask of anyone, but I truly couldn’t have asked for a better heir.” Before Izuku can begin outright sobbing, he waves off his tears and continues, “Enough of that, let’s see it on you!”
With a hasty wipe of his eyes, Izuku turns back to the armor and hesitates, intimidated, then feels Katsuki move forward, whose presence he’d nearly forgotten for the first time in his life.
“You like it?" Katsuki asks by his shoulder, voice soft.
“Yeah,” Izuku murmurs, which is an understatement if there ever was one.
Katsuki nods, seeming satisfied with that response, and picks up the first piece of armor, motioning for Izuku to lose his coat. “Good,” is all he says as he waits for Izuku to be ready, and Izuku marvels that Katsuki is doing this himself when surely there is a servant or someone else whose job it is to perform such a task.
As Katsuki begins strapping the armor in place piece by piece, Yagi says, voice as dry as Izuku’s ever heard it, “Bakugou had a lot of opinions for the armorer. I think he spent even more time down there than I did. Nearly got himself banned from the armory for his efforts.”
“Kacchan!” Izuku laughs, a pleased flush extending over his ears at the thought of how much effort his oldest friend has put into something so important to Izuku’s life and wellbeing.
Unimpressed, Katsuki merely grunts. “Someone had to make sure he got it right,” he grumbles.
Izuku shivers and falls quiet as Katsuki’s hands slide down his chest and over his waist to secure the breastplate, movement practiced and efficient, but oh so careful, fingers dancing delicately over the fabric of Izuku’s shirt.
Sparring is one thing, but having someone dress him like this is very… intimate. Especially when it’s Katsuki breathing softly so close to his ear. Even the roots of his hair feel warm now.
Once everything is snapped into place, Katsuki says, “Stay,” as he begins calling his own magic forth.
While most people rely on incantations or runes to direct what little magic they may have, Katsuki is one of the few who do not. At least usually. His magic is much more instinctual and inherent to his own being than that, embedded and engraved deep within him.
But now he murmurs over Izuku, using his finger to draw blazing runes across each piece, the metal coming alive and blazing with fire, before coming to rest, palm over Izuku's heart.
"There,” he says with a nod of satisfaction. “No dragon flame is going to get through that.”
“Kacchan,” Izuku whispers, eyes wondering at Katsuki’s fierce, expressive face.
Before Katsuki can respond, Yagi steps forward once more with a proud gleam in his eye. “And no suit of armor is complete without a worthy sword.”
Izuku’s gaze is arrested by the shine of the hilt, the sword half unsheathed and the blade luminous with power, a tangible bite of magic pulsing from it. Reaching out with reverence, he takes the sword and unsheathes it fully, admiring the heft of it in his hands, how it moves through the air perfectly weighted and fitted to his grip, a shining beacon meant to lead on a battlefield.
The metal is a kaleidoscope of color unlike anything he’s ever seen — even Yagi’s battle sword never shone quite like this. The hilt is as intricate as his armor, branches bursting with gleaming emeralds. But Izuku doesn’t miss the scattering of rubies entwined within them and shimmering with an inner fire, and cuts his eyes across at Katsuki, but his face betrays nothing, eyes steady as ever, the banked fire in them too reminiscent of the rubies themselves to be coincidence.
When he takes a proper stance and swings the sword through its paces, he can feel the flames within the blade arcing through the air, the heat and power of it, as well as the myriad other magics ingrained within, a small piece of each person’s touch left behind to strengthen Izuku and protect the kingdom. But none so apparent as Katsuki’s touch, the sheer conflagration ready to spark to life at Izuku’s faintest behest.
“It’s perfect, thank you both, so much,” Izuku stammers with the deepest bow he can manage, overwhelmed in the best way possible with how much thought and care went into every facet of its production. He can never begin to repay them for the honor they have bestowed upon him.
Yagi touches Izuku’s back, the gentleness of which Izuku can feel somehow even through the armor, and grins, while Katsuki only crosses his arms, relaxed and content.
*
Aizawa watches with dispassionate eyes from a shaded corner of the training ground, and Izuku would think he had fallen half asleep if not for the critical judgement he can feel between his shoulder blades. While he tries not to be intimidated, it’s almost impossible when he knows this is the man that taught Katsuki, and all the other knights for that matter, how to use battle magic.
Izuku has Yoichi’s power now. He’ll be fine.
With a blast of fire, Katsuki streams forward, sword raised, and Izuku only just manages to careen out of the way of the heat licking up his side with a burst of power of his own, sword nearly left behind. Defenses open, Katsuki rams the hilt of his sword into Izuku’s back, sending him sprawling into the ground. Izuku groans as he spits grass out of his mouth in embarrassment, much too aware of their audience for the day.
Katsuki sighs behind him and then helps yank Izuku to his feet.
For the first time Aizawa moves from his slumped perch against the tree and approaches. Izuku goes still and grimaces downwards, waiting for the axe of judgment. Not good enough, he’s still not good enough.
“You have more than enough magic, to say the least, and your swordsmanship is perfectly adequate, that’s not the problem. You have to think of them together. Your sword is a tool to aim your magic and strengthen your defenses. Without your sword, your power can’t have the same effect. Not in the heat of battle.”
Izuku glances up into the heavy stare of bloodshot eyes, from one of the most enigmatic knights in the kingdom’s service. Aizawa rarely leaves the capital, his power too useful for training the next generation and securing their defense if the great dragon ever, gods forbid, breaks through enough wards to reach the safe harbor of their shining city.
“Yes, Sensei,” Izuku murmurs with determination. He’s right: Izuku has been gifted all the tools anyone could ever dream of needing — armor, swords, the great power of Yoichi, the best teachers in all the lands — and it is his duty to use them all to the fullest of his abilities, to protect all the people who’ve been entrusted into his care.
That’s all that matters. Whatever it takes, Izuku will figure it out.
*
They’re standing on the castle wall gazing out over the city as the first tendrils of twilight begin to slip over the horizon. The council meeting that afternoon had been particularly grueling, Izuku's capabilities as crown prince still much in doubt by too many courtiers, and he'd needed fresh air to clear his head, no matter how many times Yagi's reassured him that he faced much the same judgement when he was named heir.
Katsuki is pensive beside him, brow furrowed, as he seems to spend so much of his time these days, always watching, calculating, concerned even, despite how grumpy much of the rest of the castle believes he is.
Izuku knows better than that though, no matter how gruff and sharp a front Katsuki puts on.
“They're wrong, you know,” Katsuki finally says, interrupting their easy quiet. “Whatever happens, you’ll be fine — and you’ll have the rest of us for anything you can’t handle on your own. The knights are strong, and no dragon, no matter how great, is getting through me.” He growls out the last part, snarl on his upper lip.
“But it’s my responsibility!” Izuku nearly shouts with frustration. “I’m the holder of One for All.”
With a groan, Katsuki rolls his eyes. “What’s the point of even having knights if only one person is needed to defend the kingdom? You can’t be everywhere at once, and you aren’t the only one capable of defending themselves.” When he senses Izuku gearing up to argue, he continues in a tone that brooks no argument, “You aren’t alone, idiot.”
Izuku looks at Katsuki, as ferocious and implacable as ever against the first twinklings of night, and allows himself to believe in him, even if he can’t believe in himself. Not yet.
Glancing back down with a small smile and a nod, he decides to change the subject for now, satisfied. “Did I show you the fireworks Yagi taught me?” he asks, giggling, and cups his palms together as multicolored lights begin sparkling out of Izuku’s hands and up into small explosions.
“Children’s party tricks, Deku?” he grouses, but there’s such fondness in his eyes dancing with the light of the fireworks popping in Izuku’s palms that it takes the breath out of Izuku with its intensity.
Izuku beams at him. “Well, we also have to give people joy, or what is it all for?” he says and then shoots one up into the sky, an explosion of color blanketing the castle, and soaks in the delighted laughter from below the walls.
*
Training with full armor and magic heats everything up. Izuku pants, sweat dripping down his temples as his armor glows with the full onslaught of Katsuki’s fire, Katsuki no longer holding back in the slightest as he slams deluge after deluge upon Izuku with a mad, cackling grin.
Izuku’s never been so hot in his life, every facet of his being covered in flame, from his toes to the tip of his sword, and he pulls his own power around him, green lightning crackling across him as he shifts his stance and focuses it all into the blade, snapping across the charred remains of the grass and directly at Katsuki before either of them can blink.
Katsuki’s still faster though. How he moves at such impossible speeds Izuku doesn’t understand; it’s like his body can react before the magic is even aimed at him in the first place.
It’s infuriating, frankly, the way he’s able to avoid the worst of Izuku’s firepower, slipping out of Izuku’s grasp before he can feel the full force of Yoichi’s strength.
But Izuku’s quick as anything too, and he flings himself forward with another burst of lightning, hoping to catch Katsuki on his backfoot, before he can reset. Their swords come together in a great cacophony that reverberates high into the sky and sends whatever birds were left nearby scattering in its wake. Izuku snarls with determination, his desire to put Katsuki in his place for once, to prove himself, surging through him as he brings his arms back and punches forward with sheer, brute strength, smashing Katsuki in the chest and sending him flying through the air and straight back into the stone wall, countless lengths behind them.
“Fucking hell, Deku,” Katsuki coughs, breath knocked out of him as he topples forward, the wall crumpling inwards. He stares up at Izuku from where he’s crouched on hands and knees, eyes boggling. “Where’d you learn to hit like that?”
Izuku whoops with glee and then snaps to attention when he hears Yagi’s distinct throat clearing behind him. “Well done, Izuku. I daresay the entire city shook with the force of you two sparring. It certainly drove everyone out of their chambers in the castle. I believe it may be time you relegated further training to well outside the city walls.”
As Izuku grimaces in apology, Katsuki just laughs breathlessly and flops over onto his side with a thumbs up.
*
Izuku wakes with the sudden bellow of the warning horn high in the tower, the stones of the castle shifting and shaking with immense force. He hurtles into the hallway, people scattering every which way and shouting over each other, unable to be heard over the blaring horn now joined by the call of the war drums from around the city walls.
By his door Kaminari stands guard in the predawn light, his usual sunny face drawn grim and urgent. “Hurry, the Demon Lord has gotten through the wards and is bombarding the outer reaches of the city! I don’t know how much longer they’ll be able to hold him back.”
Forcing his limbs to unlock he nods with all the conviction he can summon and sets his shoulders straight and unyielding as Katsuki comes tearing down the hall, armor shining and ready for battle.
It’s time.
*
The city is chaos below them, people strewn every which way as they struggle for shelter from the explosions up above. With each scream of terror Izuku pushes himself faster and faster, almost certainly little more than a flash of green lightning in the sky, Katsuki's bright hurtling flame keeping pace at his side.
All for One, the great dragon, the Demon Lord himself is even more enormous than the hazy memories Izuku has from cowering in their village as a small boy, gigantic black wings filled with gnarled scales beating at the air and sending scores of soldiers flying along the top of the wall. The sheer breadth of the massive flames he breathes out are far larger than even Katsuki’s own, and it batters at the remaining wards around the city, booming as the barrier shimmers and shakes, clearly weakening.
It’s been nearly a century since the dragon has made it to the city itself, a complicated network of wards and warning beacons placed strategically all around the kingdom and maintained vigilantly during all that time. For them all to have failed along his path…
Doesn’t matter. Izuku skids to a halt along the wall closest to the damnable beast and raises his sword as he locks eyes with him for the first time, the wizened, reptilian yellow eyes and massive nostrils flaring with recognition as he twists in the air and screams like a banshee, the onslaught almost deranged in its intensity as plumes of never-ending fire and scrabbling claws pummel the barrier in front of Izuku. Behind him, Katsuki begins shouting orders, drawing their strongest knights into formation behind him, but he doesn’t so much as blink away from All for One, trusting the others to do what is needed. Katsuki and Shouto flank his shoulders, swords raised.
He swallows and shifts his grip, readying himself for what comes next. The power that flows through his veins was made for this explicit purpose: to protect the people from the Demon Lord.
And now it's his turn. With a scream of his own, he bursts forth, glowing armor, sword ablaze, and shot through with lightning as he aims himself right for the dragon’s heart. A wing catches him and sends him tumbling, but he rights himself and streaks under the violently beating wing and tries to tear through the thinner skin at the bottom, but for such a gargantuan creature he flips over immediately in the air, massive claws oozing with pitch-black goo lashing out to grab at Izuku.
Before the claws can catch Izuku in their grip, a burst of flame shrieks by, Katsuki screaming, “Better watch your back, you piece of shit!” forcing All for One to pivot away from Izuku midair as Katsuki’s blazing sword nearly reaches his gnarled back.
When the dragon breathes in, preparing another wave of fire, Shouto leaps forward with a great wall of ice, which immediately shatters but blunts the force of the bombardment.
The Demon Lord screeches in anger and whips his tail around, hitting Shouto across the torso and flinging him into the ward, which shudders ominously. Behind him, Izuku can see Kirishima’s huge bulk physically pushing against the barrier, his magic seeping out to hold it together against the onslaught while Kaminari sends sparks flying to its weak points and so many others rush to do everything they can to help reinforce the only thing stopping All for One from raining hellfire and destruction upon the city.
Wave after wave of flame and teeth and talons batters them back towards the failing barrier, their collective magic pushed beyond its limits as they try to find an opening on the most gruesome beast the earth has ever had the misfortune of bearing.
Panting, with sweat and blood dripping into his eye from a new cut on his forehead, Izuku desperately tries to think. Everything hurts, a pulsing sort of pain emanating from his head to his toes, as every inch of him has been smashed at one point or another.
Katsuki pops up beside him as Shouto tries to distract the dragon with great lances of ice that make him roar and snarl but don’t quite seem to leave a mark. One of Katsuki’s arms is bent slightly, unnaturally, and there’s blood on his teeth as he grunts with narrow-eyed tenacity, no matter how spent and exhausted he clearly is. He spits blood and then huffs, “I’m going in on the front, I’ll make sure he keeps his attention on us. Whatever happens, you stay quiet and out of sight until there is a godsdamn opening, you got that?”
“Kacchan,” Izuku whispers, worry welling up from deep within at the rough sound of his voice, the amount of blood coming from seemingly everywhere.
All for One’s face turns away from them momentarily, and Katsuki growls and stares into Izuku’s eyes, “I’ll get you one good shot. Make it count. Or this whole city is going to fall.”
Izuku nods, the kind of clarity only solemn determination can muster settling over him. He has to make this work, there is no other choice.
Peeling off to the side, Izuku watches as Katsuki rushes back into the fray, a shrieking ball of flame that could rival the sun in its strength. Shouto and Katsuki take turns running at All for One with every bit of magic at their disposal, wild magic flinging itself in every direction as Izuku tries to creep around from behind, waiting for his opportunity.
For one moment, Katsuki hovers in the air, eyes alight and wide grin firmly in place despite how much pain he must be in, and the sun catches the hair spilling out from his helmet, the slope of his face, his fierce joy in his element, and Izuku’s breath stutters with the weight of sudden realization at just how beautiful he is, the most gorgeous man Izuku’s ever known. To him at least…
Fuck.
Izuku doesn’t have time for the way his heart lurches anew from something other than the struggle to take in air, the way his hands begin to sweat as warm affection surges through him. Kacchan will be so disappointed in him if he fucks this up because he lost his concentration over the shape of Kacchan’s smile.
Shouto stumbles and Katsuki screams in rage as the Demon Lord turns from him, before flashing forward and burning like molten lava, a great arc of fire headed straight for the dragon’s heart. With a screech great enough to topple buildings, All for One lashes out with his tail once more, nearly missing Katsuki, but managing to catch him at the last second and send him flying into the barrier, where his head snaps back and his body begins to fall.
There’s no flame, no attempt to catch himself, just Katsuki’s limp body toppling down to the earth, and Izuku’s heart stops cold in his chest, vision growing distant with fear and rage. All for One seems to sense an opening of his own and he swivels to charge after Katsuki with a breath of fire, while Shouto shoots down after Katsuki himself, ice and flame flowing in his wake.
Whatever thoughts of stealth or surprise Izuku may have had have evaporated, only blood-curdling fury left, as Izuku screams and launches himself forward in a sweep of green lightning and pure flame at a speed greater than conscious thought, only one aim in mind, his legs and sword sweeping forward to smash into the dragon with every ounce of strength and magic he has in his body.
They collide faster than the Demon Lord can react, Izuku punching into his gut and under his scales, thick, black blood sliding up his legs and sword as they careen backwards with the force, away from the city and plummeting into a field, rubble soaring around them as the bury into the ground with the strength of an earthquake. When Izuku tries to wedge his sword in even deeper, to find something vital and make it hurt, the great dragon manages to wrap his talons around him and fling him away, back into the air, before taking off towards the border in great screams of pain, blinking out of sight as Izuku lands hard on his side, head ringing.
Not that Izuku stops to consider any of that as he hurls himself towards the city, towards Katsuki, in a flash of desperate, terrified green lightning, unheeding of his own injuries.
Katsuki is in front of the city wall, back on his feet and looking near frantic himself, as Shouto tries to hold him back from following the fight, but he calms when he sees Izuku skid to a halt with no dragon in sight.
Unable to stop himself, Izuku falls on Katsuki, wrapping him in a hug, as he cries, voice hoarse, “He’s gone. For now. He’s gone,” and Katsuki’s arms slowly sneak up for a squeeze of his own as he sighs.
The great dragon will be back, but it's enough, for now.
Izuku's exhausted, utterly dead on his feet, but as he begins the limp back to the castle half hanging off Katsuki’s firm shoulder, a crowd begins to swarm. Even dirty and battered, his armor still gleams from within, and he raises his fist as his people cheer him, their crown prince, for the first time.