Chapter Text
In the month of the Horsebow Moon, Saint Seiros set forth to the Brionac Plateau. She stopped at a town called Tír Chonaill, and the lord welcomed her to lodge in his home. There, he told Saint Seiros of the demon Byleth. She cared not for whoever came across her path, be they innocent babe or veteran soldier - she slew them all, whetting her relentless appetite for destruction. The plains of Mag Tuireadh used to be one of the most beautiful places in all of Fodlan, but now it was now an eerie graveyard, littered with corpses, the rusted and decayed wreckages of carts and wagons, and roiling fog that blanketed the plains on all but the clearest of days.
Deciding that she could risk no other life, Saint Seiros departed the next day to Mag Tuireadh. The plains were completely still, lacking any signs of life; not even wind dared to pass through. On the second day, the saint found the demon at a blossoming strychnine tree, the rotted bodies of ravens littered at its base. The demon’s gluttony was so great that she devoured even the portents of death.
Manuela had decided to teach the Blue Lions for a 'change of pace', while Hanneman had elected to teach the Golden Deer. It left her with looking after the Black Eagles, to which she took no particular issue. Edelgard must have convinced Manuela, after all: the former diva had a lingering fondness for the Empire from her days at the opera. Hanneman, her opposite in many aspects, had actively avoided all associations with the Empire, even though she knew hazily that he was of Imperial birth. Ever since his arrival, he had chosen to spend all of the feast days that had passed in his laboratory, or at best, out to the cathedral to listen to a hymn or two.
On the first day of class, Byleth met the Black Eagles on the training grounds instead of the classroom. Edelgard, Hubert, and Ferdinand (the orange haired boy that had been in Edelgard's team during the hunt) came first, and she had been conversing with Edelgard on the more specific details of the syllabus when a few unfamiliar faces trickled in.
"I'm Professor Byleth." She said, once all the students were accounted for. "You there." She pointed her sword at a short girl with messy purple hair at the end of the group. She felt like a small, timid mouse. "Introduce yourself."
"M-m-m-meeEEE?!?" The girl stammered, her hysteria causing her to almost shriek. She looked like she was going to faint, which was not an uncommon occurrence in her presence, but if she could conquer her fear of Byleth, she could wade fearlessly into any other battle.
"You." The professor repeated, walking up to her, but another unfamiliar face blocked her path, holding her arm out in front of the purple-haired girl.
"That's Bern - Bernadetta von Varley, professor." This second new face didn't look too pleased, but she wasn't intimidated by the demon, either. "I am Dorothea Arnault. I hope you don't intend to start off all your classes by scaring the life out of those you teach?"
"I ask for only half." Byleth grinned, showing teeth. Her gaze bored into Dorothea's eyes for a few moments, then she turned her attention to her next target. To her credit, Dorothea didn't flinch - but there was a slight tremble in her clenched fist.
The last unfamiliar face was a Linhardt von Hevring, who was yawning and leaning against another young man, who was grudgingly holding him upright. "Come on, Linhardt, it's our first day!"
"And so early . Just let me have a couple more minutes..." He mumbled, but the young man - Caspar, thought Byleth, vaguely ferreting it from her memory - shoved him with his shoulder.
"Hey! I'm not a pillow!" Caspar complained.
"Mn, you're not a good one, anyway. Too hard and lumpy."
"WHO'S LUMPY--?!"
Her class had some fight in it, which was always a good sign. "Focus!" Byleth barked, and the class quieted, some of them looking sheepish and others (well, just one) terrified. "There will be time for you lot to embarrass yourselves later. Daylight's burning."
The rest of the introductions went more smoothly, but Byleth already had a decent impression of the ones who had attended the hunt. Petra Macneary was already an excellent hunter and deft at handling blades and bows alike. Caspar von Bergliez was an otherwise good fighter handicapped by his complete fecklessness. Ferdinand von Aegir was a good lancer, in his element on horseback, and Hubert von Vestra was an obviously talented black mage. Edelgard...
It seemed incongruous with her image, but Edelgard seemed to only have learned how to fight recently. Her movements were fluid and she handled an axe skilfully, but they lacked that physical awareness, of feeling an extension of her weapon as a part of her own body that came only from a lifetime of combat. Her tactical instincts, while adequate, belied an inexperience that no amount of wargames nor training drills could polish. Her classmates might look to her as a leader, but no soldier in the Imperial Army would realistically take direction from her in a real battle as she was.
Today was a day to start hammering out a training plan for her class, so Byleth paired them up: Caspar to Petra, Hubert to Linhardt, Edelgard to Dorothea and Ferdinand to Bernadetta. To grow, her students had to be challenged, and she had chosen the pairs based on maximising the contrast between the two's fighting styles and how they would take advantage of each other's weaknesses. The demon watched them fight, Caspar struggling with Petra's agility and Bernadetta firing at Ferdinand as she ran away from him in pure panic and terror. Linhardt had been firing off his spells in quick succession, pinning down Hubert, who was forced to divide his attention between dodging Lindhardt's white magic spells and focusing on casting his own black magic spell, which generally required a few moments to ready.
Byleth stepped into one of the duels every now and then to correct any errors she had seen and advise what they should be doing to work on their deficiencies. Bernadetta was going to be a work in progress, but she pointed out to Hubert a few ways he could shorten the cast time of his spells. Casper, being such a close-range grappler and fighter, would need to be faster in his movements to take the momentum of the battle and overwhelm his opponent.
As she predicted, Edelgard was having a bit of trouble with Dorothea, a significantly faster opponent. Edelgard was no slouch, but the natural weight of the axe meant that her attacks were slower. Dorothea was able to dodge her swings and counter with a stinging cantrip, or strike her with the flat of her training blade.
"Stop for a second, you two." Byleth interrupted, and the pair stopped, Dorothea dabbing at her sweat with a handkerchief. "Edelgard, your stance is too wide."
"What?" Edelgard furrowed her brow, but Byleth was already walking up to her. The professor placed her hands on the young woman's hips.
"You're making your stance too wide to compensate for your lack of range. It makes you less stable and you're less agile when you turn around." She squeezed slightly with her palms, prompting Edelgard to shift her legs closer together.
Edelgard seemed lost for words, and by the growing heat of her cheeks, she seemed to be embarrassed that her skill was found wanting on the first day of class. "Shoulder width is what they teach during training," Byleth continued, "but keep in mind that other fighters typically have a higher center of gravity, and thus need a wider stance to steady themselves."
Resting her hands on her student's wrists next, Byleth continued. "I noticed that you react instinctively and try to change the direction of your swing mid-swing. You must learn to suppress it. Once you throw an attack, follow it through in a circle-like manner to dissipate the energy of your swing." Leaning in, she guided Edelgard through a few swings, demonstrating how much easier it was to adjust her movements from one swing to the next using the momentum from her previous attack.
"It'll then be easier to make a parry or block, and then you can disarm your opponent with the hook of the axe blade, or throw them off balance. Dorothea, try and strike Edelgard." Byleth backed away a few paces to give the two space, and Dorothea darted forth, thrusting with her blade.
Edelgard quickly stepped to the side, but Dorothea was already swiping with her sword. She blocked it with the haft of her axe, and quickly shifted her grip further down the handle, sliding the blade up into the hook. Edelgard tugged - hard, and Dorothea yelped in surprise as she lost her grip on the sword and fell forward onto the soft grass.
"Nice work. You picked up on the technique up right away." Edelgard said nothing, though she seemed rather pleased if a bit bashful. Byleth helped Dorothea get to her feet, who looked chagrined as she brushed little bits of grass and leaves off of the front of her uniform. "Now, Dorothea, when you're facing an opponent with greater physical strength, here's how you can redirect it..."
Byleth continued training the class in this manner for the next few weeks, rotating pairs so everyone had an equal amount of time squaring off against each other. By Friday evenings, they would be running on fumes from five full days of training, so the demon used Saturdays to run war games and talk historical strategy in the classroom, while also giving them a day of physical rest.
The mock battle at the end of the Great Tree Moon was typically a simple evaluation of students’ abilities to see how they would do in combat, but in lieu of her thirst for destruction and death, an all-consuming desire for victory had sublimated in Byleth. The stringent training Byleth had put the Black Eagles through meant that they were more than equipped to deal with the opposing Houses. They had been attacked so aggressively and quickly right from the start, that they had to immediately take the defensive, and from then on had lost the momentum of the battle and was never in a position to recover and start pushing back.
While the other two were good professors, no class under Byleth’s charge had ever lost a clash between Houses. The mock battle was a complete rout in the Black Eagles’ favour, and to their credit, the Blue Lions and Golden Deer accepted their loss gracefully. The Black Eagles too were gracious winners, and Byleth wouldn’t suffer her students to gloat. A win was a win, but it was only one win.
The class celebrated together in the dining hall that night, cheering each other over dinner with granatus and clarea. They would discuss elements of each other’s combat style that had caught their eye, what they thought could be improved, and later into the evening, share gossip about each other’s lives and life at the monastery, but Byleth had not been with them. Instead, she had been at the knights’ hall, which, at dinner time, was deserted. She had been working in solitude and blessed silence for the better part of an hour when she felt her approach.
"Another year like this?" came Rhea's voice. Byleth didn't bother looking up from the grindstone.
"I told you before. I have no interest in fraternizing with every single class that passes through." Byleth tested the sword she had been sharpening on a piece of scrap wood, which cut cleanly in two. She wiped its edge with an oiled cloth. "I forge them to be better warriors and generals. That's about it."
"And yet a few decades ago you would have said any student of yours would either keep up or die." Rhea was only a few paces behind her now. "I daresay your opinion has shifted, and will continue to change."
"A broken sword is good for nothing but scrap." Byleth admitted. "But the weaponsmith doesn’t get attached to her wares."
"Is that how you perceive yourself?" The archbishop put her hand on her shoulder, but Byleth shrugged it off. “I find that a long life is best lived with company.”
“Oh?” Byleth rose to meet Rhea, sheathing her sword in the weathered scabbard on her belt. “Acquainted with a well-lived life, are you?”
Rhea was silent for a few moments before she answered quietly. “No.”
Byleth had a stinging barb readied, but it would only pointlessly antagonise Seiros. Sacrifices had to be made. "I'll consider it." She conceded. "I wouldn't consider myself good company, though."
"On the contrary, Byleth, I much enjoy yours." With that, the archbishop left, leaving her to ruminate on her words in the dying cinders of sunlight.
Two weeks into the Harpstring Moon, Byleth had been summoned for a meeting with Rhea, Seteth and the captain of the Knights. When she entered the council room, the others had already gathered.
"Don't start, old lizard." Byleth snapped, before Seteth could start. "I just finished my afternoon classes with the very same hatchlings you have sent my way, so be quiet for once in your misbegotten life."
“Byleth.” Rhea warned, her tone low in admonishment. Though she was often indulgent of Byleth, Seiros never brooked an insult towards Cichol while she was around. Her hand, Byleth noticed, stayed on Seteth’s arm, preventing him from rising to meet the demon.
Byleth didn’t respond, instead electing to sit a few chairs away from the both of them.
The captain cleared his throat, and started things off briskly. "We have yet to determine the identity of the perpetrator behind the attacks on the heirs during the hunt, but one of our contacts in Faerghus have determined the mercenary company the assailants belonged to - Gallowglass. They compose mainly of Kingdom knights, but a significant portion of their ranks draws from other countries like Brigid and Dagda."
"Who leads them?" Seteth asked.
"A former Faerghus warrior, Somairle. Common birth, no connections to speak of. They operate out of Gaspard." If these mercenaries were under the jurisdiction of the Bishop...
"Upon your instruction, we approached the Western Church and requested their assistance in detaining members of the company for questioning in investigating the attempted assassination of the heirs. Their response, uh, was less than welcoming."
"Meaning?" Byleth prodded.
"Um..." The captain looked truly uneasy at this, and he was evidently hoping he could gloss over whatever it was the Western Church said. "I... have a letter containing their response. I place it at your disposal." He produced a scroll from his cloak, and Byleth took it, unfurling the scroll to see.
"Captain Aedh mac Felim,
I have received your letter regarding the inquiry into the existence of the mercenary group Gallowglass in Gaspard. The Church of Seiros takes only an advisory role in governance, and we would not be able to aid in this matter as Lord Gaspard alone decides what actions to take regarding his titles.
Furthermore, the claims that Gaspard harbours such lowlifes that would threaten the life of their future king is an extraordinary claim that is surely backed by the existence of extraordinary evidence. If proof of such claims can be produced to us, we would act as the intermediary between Lord Gaspard and the Central Church and aid in rooting out such sedition.”
“Only an advisory role?” Here, Byleth laughed out loud at the absolutely preposterous claim. “Everyone knows Lonato does not as much blink or sweat without the approval of the Bishop!”
“Not that any evidence we produce will meet their standards.” Seteth replied. “They would never tolerate any agent of the Central Church in their territory, especially regarding such a serious breach of security that may very well mean treason. Worse, they could twist this into some sort of attack on the independence of the Western Church or even Faerghus itself. Anyone in the area trying to find more information on this mercenary group might be regarded as an agent of the Central Church. It might be more prudent to leave this matter to be investigated at a later date.”
“Yes, and by then, the company would have scattered to the four winds, and the trail would have gone cold!” Byleth retorted, frustration bubbling out of each syllable. “The Western Church has been a serious thorn in our side for a long time. I suggest that arrangements be made for their cooperation to be secured on a more permanent basis.”
“No.” Rhea finally spoke, her demeanor serene though Byleth knew her to be pained by this turn of events. “The sovereignty of Gaspard and the Western Church must be respected. They clash with us on a great many things, but we are still of the same faith. We must do what we can to heal discord in the community, not take advantage of it for selfish ends. I cannot allow it.”
Mentally cursing her slip of the tongue, Byleth tried to salvage the remnants of her dignity. “Then there’s nothing left to discuss.” she scoffed. “Without the Western Church, Gaspard would never cooperate. The Knights of Seiros have no authority to operate in the region, and the point of contact for the assassination would either be dead or long gone. Nobody will ever know who ordered the hit. This has been a grand waste of time.”
Seteth watched Byleth leave. “Will you not stop her?” He asked Rhea.
“You heard her, did you not?" Seiros smiled gently at her brother. "In this regard, our concerns are her concerns. Rest assured, Seteth, that her heart is in the right place.”
Byleth had stormed off to her office, but only so she could write a brief note. She looked out the window, and a raven stood on the windowsill, a insect in its beak.
Her eyes were upon it immediately, and the raven seized up, remaining frozen as she tied the note to its leg. Blood started to collect at the corners of its eyes.
“ Carry this message .” She commanded harshly, and it jerkily hopped off the sill, recovering and flying stiffly off towards the west. The bird would die just as it would reach its destination, but that was more than sufficient. She simply required her recipient to receive the message.
Three days later, Lord Lonato Gildas Gaspard declared war on the Central Church of Seiros.
The three Houses had been dispatched to Gaspard as the rear guard to mop up any remaining opposition. The bulk of the Knights’ forces had moved a few days prior and blockaded Castle Gaspard, but there might be pockets of resistance in the sprawling forests around the castle, stragglers that had believed they could win. It was stupidity, of course, but much of human history had been built on vain hope.
Loathe as Rhea had been to let Byleth enter battle, the timing of this opportunity was perfect. Finding evidence of treachery would be the leverage they needed to push against the Western Church and continue investigating Gallowglass. Hanneman and Manuela were also leading their respective Houses, and Catherine had been dispatched to lead the knights that the classes would be accompanying. The wielder of Thunderbrand had approached her at the gates of the monastery, where the students were preparing to depart for Gaspard.
“So you’re finally being called into battle, huh?” Catherine asked as Byleth was adjusting her horse’s tack. “Gotta say, I’m pretty excited to see the Ashen Demon in action.”
“Is that all you'll be doing? A greater share for me, then.” Making sure that the saddle was properly fitted, Byleth looked back at Catherine, a slight curve at her lips the only indication of her excitement for the bloodshed ahead.
"Of course not!" The young knight scoffed. "I just want to see what gave Saint Seiros such a hard time."
“Watch then, if you must. You may learn something.” Taking the reins of her mount, she sauntered off, leaving Catherine behind.
Gaspard was relatively close to Garreg Mach, but it would still take a day cutting through the Magdred Way to arrive at Cambiac, the town below Castle Gaspard. Cambiac had been taken days ago, and they were to rendezvous with the Knights of Seiros and aid them in their assault on the castle. Though they were travelling by horse, the heavy fog had forced them to slow to a trot, the poor visibility making it dangerous to go any faster. The students chatted with each other to pass the time, while Catherine and Byleth kept on the alert, the Knights forming a loose box formation around the Houses.
"Why do you think Lonato suddenly turned on the Church?" Casper asked out loud to the Black Eagles.
"The Western Church of Seiros is headquartered near Arianrhod, so its influence is strong in Gaspard." Ingrid replied. She had joined the class last week, and was slowly getting to know the others. "Additionally, Lord Gaspard's relationship with the Central Church has been rocky ever since his son was found to be implicated in the Tragedy of Duscur, and executed by the Knights."
"His son… so, like, Ashe's brother?!" Casper exclaimed, shooting a look backwards to where he was riding with the rest of the Blue Lions. He looked pale, as if he had taken ill.
"Yes, but Ashe isn't related to Gaspard by blood." Dorothea joined in, riding up next to Ingrid. "He was adopted into the family as a young boy."
"So Lonato wants to get revenge? But why only now?"
"He never accepted that his boy was guilty." Catherine responded this time, grimly looking forward. "I guess it ate at him all this time. It would have been his 25th birthday on the 17th. Now pipe down over there, we're inside enemy territory."
The students quietened. Any subject that Catherine was this laconic about was clearly one she did not enjoy discussing. The omnipresent fog had now thickened into the consistency of cream, blanketing the forest in an ocean of clouds.
The sound of galloping horses echoed from the distance, and Catherine stopped, unsheathing Thunderbrand. Red electricity crackled along its jagged edges as it reacted to its bearer.
"Halt!" she yelled. "Identify yourself or answer to Seiros' blade!"
The gallop slowed to a canter, and out of the fog emerged a few scouts bearing the Church’s colours. "The enemy is approaching!' panted one knight.
"What?!" Catherine demanded, sliding off her saddle and walking to the scouts. "How close are they? What are their numbers?"
"Far greater than we initially predicted. They must have used the fog to slip past the perimeter around the castle." Again, there was the distant thundering of hooves, and Catherine swore.
"Looks like our mission just changed. Everyone, prepare for battle!"
Many scrambled off on foot, grabbing whatever weapons and supplies they had packed, but Byleth calmly rode forward to the front of the troop.
"Lancers!" She commanded. "Form a shield wall, spears out!"
This was why Byleth had been dispatched. This was why she had been kept alive at all. Knowing not to hesitate, knight and student alike packed tightly against each other, weapon and shield in hand. Their overlapping bulwarks formed a barrier that blocked the only path through the Magdred Way.
"Mages. Prepare your fire spells."
The soft glow of sigils lighting up behind Byleth told her that the mages would hold the spells until she gave the signal to fire. The thundering was now terrifyingly close, and the ground shook with the stampede of dozens of warhorses. It wouldn’t be long now.
"Archers! Curved shots. On my signal…"
Dark shadows started to take shape within the fog. Byleth raised her left hand, her right hand gripping her sword -
"FIRE!"
With a cut of her wrist, the archers loosed their arrows, the high angle of their shots falling like rain onto Gaspard's knights. Soldiers cried out in pain as arrows bit into exposed joints and flesh and many more clattered against their armour. Their horses slowed, wary of the impenetrable wall with sharp sticks pointing out -
At that moment, the ground they stood on burst into flame. Screams rang into the air as the rebellious knights frantically tried to beat out the fires on their armour. Panicking, their horses bucked off their riders in a bid to run from the conflagration. The heat evaporated the nearby fog, allowing the Church forces their first look at their foes.
Behind the cavalry charge had been Gaspard's infantry, which were now being charged by burning warhorses. The militia had panicked and scattered, their ranks breaking and many being trampled by their own mounts. Lonato's vanguard had crumbled, and the Knights of Seiros had yet to take a single scratch.
Catherine thrust Thunderbrand forward. "CHARGE!"
Avoiding the raging fires, the Knights advanced on Gaspard's forces, followed by the students. Steel clashed where the main body of Lonato's formation met the Church’s forces. As the Blue Lions broke through Lonato’s frontline, and the Golden Deer followed closely behind, Byleth briefly paused to speak to the Black Eagles.
“We will hunt down Gaspard. Follow closely, and in files of two.”
The small group tightened into a column, and Byleth ignored her impulses and the battle raging around them. Pausing only to run her blade through rebels ill-advised enough to aim an attack at any of her students, Byleth cast her eyes around for any sign of the commanders, but found nothing.
"You think we're going to do nothing while you try to kill our--" The militiaman was cut off by a swift kick to the face, sending his sword flying and him sprawling into the dirt. Byleth dismounted, and approached the reeling soldier. The Black Eagles hung a few steps behind.
"Where is Gaspard?" she questioned, looming over him.
He looked up, staring at her hatefully even through a shattered nose and broken teeth. "I'd never tell you, abomination!" He spit out..
Byleth squatted onto her haunches and forcefully grasped his face, ignoring his scream of pain. "You are going to die today." She growled. "You can either pass, quickly and painlessly, and your family can have an open casket at your funeral, or we can find out how many senses a human can lose before they die." Her clawed gauntlets hovered perilously close over his eye sockets.
His bravado instantly gave way to fear and dread. A few moments passed where the demon could tell his loyalty to his liege wrestled with his sense of self-preservation. Finally, the soldier choked out, "H-he's with his honour guard, at the rear. But you will never defeat him, the Goddess is with him!"
"Good choice." Byleth quickly produced a knife from her sleeve, and with a singular fluid motion, sliced open the artery in his neck. She got to her feet and kicked his limp corpse, rolling it out of her way. Linhardt and Dorothea averted their gaze uncomfortably, but there was no escape. Better that they accepted the realities of war now, that they may be stronger for it.
The fog was starting to lift now. Given how unseasonal it had been, and how it was suddenly dissipating, whoever had cast it must have been slain. Looks like Catherine is earning her keep, Byleth thought as she struck out on foot. As for Lonato himself, he would surely be watching nearby in an advantageous location, perhaps on higher ground, or a choke point. All she had to do was find him.
As the weather cleared, it quickly transpired that Lonato had made no attempt to hide himself. Three mounted knights surrounded him, all bearing the standard of Gaspard, atop an outcropping of rock on a grassy knoll. He seemed impassive, as with his guards: they seemed to be content waiting for the Knights of Seiros to come to them.
Byleth turned to her students. “Fall back and regroup with the Knights.” She warned her class. “Tell Catherine Gaspard is here.”
Ingrid started, perhaps meaning to argue with her on how they wished to fight, but Byleth cut her off. “Save it. These are experienced soldiers you’re dealing with, not some villager who’s too in over his head or a glorified doorstop. Do you understand? If you face them, you will die.”
“I’m not afraid of death.” Ingrid challenged.
“You shouldn’t be. But there are worthier battlefields to die on.” Byleth started walking towards Lonato, sword in hand. "If I turn and I see anyone still back there, I'm failing you!" She called out.
The Black Eagles laughed, but one by one, the beat of their horses’ hooves faded into the distance. Only one seemed to linger, but when she turned her head, they were all gone.
Her skin buzzed with an eager, anticipatory energy.“Vile beast of darkness, you pollute the very land you walk with your filth!” Lonato snarled, raising his lance and pointing it at her as she closed in on him. “In the name of the Goddess, I will pass judgement upon you and the Central Church!”.
Had he truly desired victory, Gaspard would have never emerged from his castle, or at the very least, fled this lost battle. Instead, in the face of certain death, he defiantly stood his ground. He clearly desired a warrior's death, and Byleth would grant it to him.
It was over in seconds.
As she thought, Lonato had been carrying letters. The first was unopened, still tied with cord and its seal intact, but the wax on the second letter had clearly been broken. Even in pieces, the shards still unmistakably bore the seal of the Church of Seiros.
"Byleth!" Catherine yelled, her voice far behind. "Did you find anything?"
Byleth tucked the second letter inside her cloak, and held up the first. "Just this one letter."