Chapter Text
What if…? What if the Lion had claws?
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Both were in the gardens of the Karsten Mansion estate that day.
It had become almost a weekly or monthly routine for them to train together under those circumstances — a sparring match between an older man with purple hair wearing a knight's uniform, and a well-dressed young man.
The young man had dark green hair with black streaks in his bangs, along with intense, glowing eyes — a mix of his mother’s and father’s colors — and wore a simple, slightly worn training outfit. They stood face-to-face.
The youth held a wooden sword, while the older man wielded a real one.
Julius Juukulius, the Finest of Knights, was facing off against Leo Natsuki Karsten, the First Prince of the Kingdom.
It was one more bout in their regular training sessions, the long-haired knight giving it his all to overcome his opponent.
A soft breeze swept through the trees surrounding the mansion's wide training ground. The grass was well-trimmed, and the mid-afternoon sun filtered through the branches, casting dancing shadows on the ground.
The sound of wood clashing against metal echoed through the air.
Julius Juukulius breathed deeply. His usually calm and confident expression was slightly strained — a rare sight. In front of him, standing with relaxed posture, calm eyes, and a worn wooden sword in hand, was Leo Natsuki Karsten, heir of the house.
[Leo: Hah... You’re not really putting pressure on me, Julius.]
He said this as he effortlessly sidestepped another thrust, twisting his wrist in a smooth, fluid motion.
Julius stepped back twice, adjusting his stance. The spirits around him whispered, lending their strength to the Spirit Knight. He was preparing once more to face his young opponent — though fatigue was starting to show.
Fragments of magical light began to float around his blade.
[Julius: Even if this is training, I can’t afford to underestimate someone of your skill, Leo-sama.]
[Leo: You're not underestimating me. You're trying too hard to make up for the difference... That makes you slightly predictable, Julius-san.]
Leo shook his head, a faint smile on his lips.
Before Julius could respond, Leo advanced.
It wasn’t an aggressive or explosive attack — it was clean, direct, and terrifyingly efficient.
Julius barely had time to raise his sword before the impact struck the base of his blade. His guard shattered.
Clack!
With a sharp snap, Julius’s sword flew into the air. He reflexively stepped back, but Leo had already stopped, still in the same calm stance.
[Julius: Tsk. You really don’t hold back, even with a wooden sword.]
[Leo: That’s the point of using wood. So pain teaches — but doesn’t kill. Again?]
Leo replied almost instructively, spinning the staff in his hand and returning to his starting position, watching the slightly winded knight in front of him.
Julius retrieved his fallen sword, this time surrounding it with a more intense aura. The blade shimmered with elemental magic — lightning and wind intertwining around it.
[Julius: Yes. I won’t retreat from a challenge from you, Leo-sama.]
[Leo: Admirable. But remember... you can also learn by losing. As long as you pay attention.]
This time, Julius launched into a complex sequence of spinning slashes.
It was a refined dance of technique and magic — speed, precision, power.
Each strike aimed to push Leo back.
And yet, the young man didn’t retreat a single step.
Leo dodged calmly, using the bare minimum movement necessary, as if studying Julius’s choreography. Then, at the end of a pirouette, when Julius came down with a charged overhead slash, Leo parried it with a single motion and spun the staff — tapping Julius’s abdomen lightly with the butt of the weapon.
Julius dropped to his knees, breathless, the pain reverberating like a blow from a warhammer.
He stood again and charged at the green-haired youth.
Each step made the ground creak beneath his boots, his sword cutting the air with strength and precision. The magical blade shimmered in spirals of wind and elemental energy, spirits hissing around him, amplifying every strike with bursts of light and force.
And Leo... remained still until the last second.
He dodged with the grace of a leaf in the wind, moving in tight lines, heels nearly floating above the grass.
When he blocked, it was effortless — as if his wooden sword was custom-made to slip between the gaps in Julius’s form.
Julius spun. Thrust. Leapt. Struck with both hands.
He used bursts of wind to expand his reach, surrounding Leo with illusions of simultaneous blades.
Leo cut through all of them with a single fluid motion.
Julius roared in silence, pushing his body to its limit.
His breathing now heavy.
Temples pounding.
Sweat dripping from his chin.
He dashed in erratic lines, seeking improbable angles, even abandoning proper form in hopes of making Leo step back just once.
Nothing.
Leo still breathed calmly. Eyes unshaken.
Feet showed no tension, no rush.
His arms moved with inhuman precision, as if they already knew where Julius’s next blow would land.
And when Julius tried to break the pattern with a charge powered by elemental magic — lightning dancing across his blade, the air around him bending — Leo responded with a slight twist of his waist.
CRACK.
The wooden staff landed with a dry thud on Julius’s shoulder, throwing him off balance.
Before he could fall, Leo spun the sword and swept Julius’s supporting leg with a second, soft but precise strike.
Julius fell.
But he did not stay down. He rose again. Staggering, knees unsteady, chest heaving in short breaths. But his eyes… remained sharp. There was something in them — something beyond pride. A silent fire — not fighting for victory, but for dignity.
He didn’t call for a break. Didn’t announce his return.
He simply advanced.
No magic. No spirits. Just raw technique, distilled to its core. His sword trembled in his hands, but still sliced the air with perfect aim. His feet scraped the ground, but still knew where to land. He moved like a man who knew he would lose — and still chose to fight.
Leo received him as before: upright stance, steady eyes, calm breathing.
No emotion. No hesitation.
The wooden sword intercepted the first strike. Then the second.
The third was deflected with a smooth twist of the wrist that brushed Julius’s blade aside like it was straw.
Julius threw a kick — quick, unexpected.
Leo pulled back his leg, letting the foot pass harmlessly — and answered with a short tap to the shoulder using the staff’s edge.
Thok.
Julius spun through the air and hit the ground, rolling across the grass.
He coughed. A light scratch on his elbow bled.
Still, he stood again.
He took three steps. And ran. This time, he charged his sword with minimal magic — not to attack, but to accelerate. He tried to be less predictable, less forceful. Used short rotations, random slashes, feints.
Leo, still expressionless, didn’t take a single step back.
It was enough to throw off Julius’s rhythm entirely.
A short tap to the calf — and his leg gave out.
He fell to his knees, and as he tried to rise, a clean strike to the shoulder shoved him hard back to the ground.
Leo remained silent.
Julius stood again. Slower.
The fight became repetition. A cycle unbroken.
Advance. Slash. Dodge. Counter. Fall.
Each time Julius returned with less strength, but never with less resolve.
It was an uneven duel — the desperate perseverance of a man against the brutal serenity of a prodigy.
The air around them grew hot with Julius’s exertion — and impossibly still around Leo.
Even after twenty, thirty exchanges — Leo hadn’t lost his breath.
Hadn’t broken a sweat.
Hadn’t lost his balance.
It was like trying to cut through a current with a dagger.
Julius, on the ground once again, propped himself up on one knee. Blood trickled in thin lines down his face. His hair clung to his forehead. His hands trembled. But his eyes—still open, still burning. He wouldn’t give up until he managed to land at least one hit on the young green-haired boy!
With a near-inhuman leap, surrounded by light, he rose again. He charged forward, eyes locked on his target, ignoring the rising pain in his muscles. The grass scorched beneath his feet as he slid in with speed, unleashing a descending arc that split into five simultaneous slashes through magical manipulation.
Leo spun. With a single flick of his wrist, he neutralized all five strikes, breaking Julius's pattern once more.
He stepped forward twice, slipped under his opponent’s arm, and tapped the side of Julius’s abdomen with the hilt of his wooden sword.
A light strike.
But effective.
Julius staggered, nearly falling. His chest heaved. The hand gripping his sword trembled. His shoulders were tense. His legs, heavy. Even so, he planted his feet on the ground again. He spun his sword. Rekindled its magical aura. One last attempt. He jumped.
For the first time, Leo raised his wooden sword in a high angle — as if acknowledging an attack worthy of meeting head-on. The impact was deafening.
BANG.
But in the end, Julius was repelled like a leaf against a stone wall. His sword flew far, and he landed on his back in the grass, gasping for air, gathering what little strength he had left to get up.
Leo remained standing. Untouched. The wooden sword still firm in his hand, as if everything that had just happened had been no more than a calm afternoon in the mansion gardens.
Julius was now on his knees, panting, hands resting on the damp grass marked by dozens of exchanged blows with the young Karsten heir.
Sweat dripped from his chin. His lungs burned. Every muscle in his body screamed for rest. His sword lay a few meters away, abandoned after the last blow had thrown him off.
Before him, Leo stood — unshaken.
There was a heavy silence, thick like fog. Even the spirits surrounding Julius seemed to waver, their glow flickering.
It was then that Leo, for the first time, rolled his shoulders—as if preparing to truly begin.
His body shifted position. It wasn’t flashy. No magic, no explosions, no light.
But the air changed.
As if the sky had darkened, even with the sun still high. Julius instinctively looked up... and froze.
An invisible, suffocating aura enveloped Leo.
It wasn’t magic. It was something more primal — a pure instinctual sensation. A predator.
Julius felt a chill climb up his spine, as if his body understood before his mind: He was now within range of something that could kill him without hesitation.
Leo stepped forward.
One step. Two. Three.
Each step was silent, yet made the ground vibrate. Julius tried to stand, but his body wouldn’t respond immediately.
Fear — rational or not — chained him like invisible shackles.
The calm in Leo’s eyes remained, but now there was something more: total focus.
Like a blade finally unsheathed after only being shown.
Leo raised the wooden sword.
And at that moment, Julius could swear it was steel.
No — it was like staring at death itself, taking the shape of a blade.
The wooden sword came down.
Julius’s eyes widened. Time seemed to stop. He didn’t see the strike — only felt the overwhelming pressure slicing through the air, his hair standing on end, as if a sharp gust of wind had passed through his body. For a moment, he truly thought he had been cleaved in two.
His body froze. His chest failed to draw breath. Phantom pain shot from his shoulder to his waist, even though there was no blood.
Leo’s sword stopped.
Just millimeters from the top of Julius’s head, the wooden tip trembled slightly — not from lack of control, but from the abrupt stop of a blow that, had it continued, would’ve shattered every bone in Julius’s body.
The air behind them exploded outward, forming a spiral trail that tore the grass and left a small crater behind the kneeling man.
Silence returned.
Julius didn’t move for several seconds.
Only then, with a shaky tremble in his shoulders, did he inhale — for the first time since Leo had moved.
His breathing came ragged, gasping.
His heart pounded as if he had just escaped execution.
Leo stepped back. He spun the wooden sword and rested it on his shoulder with an almost casual motion.
The deadly gleam in his eyes faded like fog under the sun.
Julius dropped back onto the grass, seated, without strength.
[Leo: Forgive me, Julius-san. I lost a bit of my composure at that moment. I shouldn’t have gone so hard on you, and I could’ve held back that last strike. I apologize for that.]
[Julius: D-Don’t apologize, Leo-sama. Apologizing for taking me seriously only makes me ashamed of not being strong enough to face you right now. It makes me feel inadequate. Wounded pride shouldn’t be something that matters in our training sessions — especially given our statuses.]
[Leo: It’s not inappropriate to feel wounded pride in moments like this. As my father once explained to me: we all act in pursuit of our personal desires. Even I acted slightly out of pride, trying to show you my strength. Out of my own arrogance and pride.
Now, in your case — there’s nothing wrong with fighting me for your own pride and the personal desire to protect your family’s honor. In those moments, allow yourself to relax... and act according to your own choices for how and why you fight.]
Speaking in a gentle tone, Leo explained with a small smile on his face.
Julius felt slightly embarrassed to receive yet another lesson from one of the kingdom’s most authoritative figures — especially when the first prince himself was quoting the king to teach him how to relax.
Even more so coming from someone known for not relaxing much at all.
Leo Karsten was a serious, focused figure, dedicated to his training and studies for the sake of the realm.
To receive advice like that — for that reason — and from someone just as serious (or even more so) than himself when it came to serving the kingdom...
In that moment, Julius stood up again, a bit worn.
Brushing the dust off his knight’s uniform, he walked over to his sword.
It glimmered faintly as he picked it up.
[Julius: Leo-sama, may I be selfish… and request another training session with you for our next meeting? I want to continue trying to discover the limits that you, my prince, possess with my own eyes. I want to face you head-on once more.]
[Leo: With that... we’ll have faced each other around a hundred times total… and I already carry 99 victories.]
[Julius: Then you won’t mind earning your one hundredth victory over me, right?]
Teasing more casually, the man couldn’t help but feel a bit of pride in coaxing a small laugh from the normally too-serious green-haired boy — almost as serious as himself.
[???: Those kinds of things are mildly embarrassing to say. But that truth is so strong that even I feel shy admitting it.]
[Julius: Lady Crusch-sama.]
[Leo: Honored mother, were you watching our training?]
Crusch Karsten appeared in the mansion’s garden carrying a small child in her arms. She had a gentle smile on her face as she looked at the young man alongside the knight.
[Crusch: I was able to observe from afar. I apologize if it was inappropriate, Leo. But I couldn’t resist watching your abilities bloom.]
[Leo: It is not shameful for me, nor unpleasant, to have you watching my training. In fact, I would like to face you again in the future when you have some time free from your meetings with the Kingdom and the care you give to my brothers and sisters. Even with my father’s help, I know it must be difficult for you both to manage so many responsibilities.]
[Crusch: Me, Wilhelm, Julius, and Reinhard. You face us all to continue training and growing stronger, right? I believe your father is right in suggesting that you should rest and relax more. It can be a problem if you drown yourself in so many responsibilities at such a young age. Don’t you think it would be better that way?]
[Leo: Urgh. Please, mother. For me, training is a way to relax. It embarrasses me that father thinks I’m overexerting myself when I’m just trying to fulfill my duties. Not that I dislike his concern for me and my siblings. It’s just… I want to keep pushing myself for all of us, so that my brothers and sisters won’t have to push themselves so hard.]
[Crusch: And we’re grateful for that. But I agree with your father when he says you shouldn’t carry the burden of having to try so hard all the time. So please, when you’re tired, don’t push yourself beyond your limits. Remember to rest too. I say this not as your queen, but as your mother.]
Speaking in a gentler tone to her eldest son, he had no reply. Yet the three of them knew well this wasn’t something he did out of malice or obsession.
It’s just always been the way Leo Natsuki Karsten, the firstborn prince, is.
He is a powerful young man. Heir to the throne, someone who—like Julius and his mother—always takes his responsibilities to the Kingdom of Lugunica far too seriously. A commanding presence, respected, just as someone descended from such important figures in the Kingdom should be.
This young man is Leo, the honorable Knight of the Kingdom...
This young man is Leo, a youth dedicated to those who believe in him...
This young man is Leo, someone who would never back down if it meant protecting his family...
This young man is Leo, who fights to uphold the honor, respect, loyalty, and abilities of the royal family and the Karsten and Natsuki Houses...
This young man is Leo, the Lion Prince of Lugunica...
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My YouTube channel: ThinkMind.
Because I got excited, I decided to post this chapter and one from the Family IF to have some fun. But the next one will probably come only on Saturday—or maybe I won’t even post Saturday since I posted this one today.
In this IF:
-Leo is the eldest among all his 17 siblings.
-He is a very serious person who needs the help of his father and mother to remind him to relax at the right times.
-In terms of combat ability: From an early age, he’s skilled with a sword—so much so that the only one who surpasses him is Reinhard himself.
-Leo is right-handed, but he trains and fights exclusively using his left hand, since in the past, he nearly killed Julius during a training duel. Ever since, he deliberately avoids using his dominant hand so he never repeats that event. If not for Julius’s spirits healing him, the knight would’ve died during the match.
-He is considered an anomaly, much like Reinhard, Cecilus, and Halibel.
-In the past, he nearly killed Crusch by accident: He saw her interacting with Natsumi, not knowing it was his father in disguise. Thinking his mother was being unfaithful and tarnishing the royal family's name, he challenged her—and only later discovered the truth, leaving him deeply ashamed.
-Leo likes demi-humans and men. In the past, he even had a crush on Felix, but over time, he grew out of it and now sees him more like an uncle whom he deeply respects.
Extra info for those curious:
-If Leo and Helena (from my Helena IF) fought each other 50 times, they would tie in all 50 rounds.