You Used Mana
After being utterly dismantled by an elective instructor he had looked down upon, Deleve Kundel holed up in his dormitory for two days straight.
Inside his luxurious private quarters, he skipped orientation for his other lectures, endlessly stewing over the humiliation of that day. Yet the more he replayed it in his mind, the more curiosity began to supplant the shame.
Just how on earth did I lose?
It was the first true disgrace of his life. And precisely because it was his first, he found himself obsessed with understanding it. The movements that flickered at the edge of vision only to vanish. The sheer speed with which the man had slipped behind him, relentlessly tripping and subduing him without a moment’s pause!
To Deleve, who had held his ground even when sparring with his family's apprentice knights, an entirely new world had been revealed.
It was the world of defeat.
Dozens of defeats, suffered in the span of a single afternoon.
It was never like that before.
House Kundel's martial philosophy was straightforward: grow stronger through defeat. And every defeat Deleve had tasted until now had adhered to that tenet. You exchanged blows, you fell, you listened to sharp yet encouraging critique, and then you rose to swing your blade with renewed vigor. He had assumed that was all defeat ever was.
The defeat inflicted by Instructor Xiel Steelheart, however, was of an entirely different nature.
He dismantled me completely, again and again.
The moment he hit the floor, all he received was a curt piece of feedback. Immediately after, he was mercilessly swept off his feet once more, sent tumbling across the ground dozens of times. It was agonizingly humiliating.
Yet, why had it felt so different?
Over the course of those dozens of falls, Deleve had found himself gritting his teeth. He strained with everything he had to stay on his feet, replaying every shift in his posture the instant it happened. And near the very end...
I felt something.
He had definitely caught a glimpse of something, even if he couldn't put into words what it was just yet.
Deleve wanted to nurture the talent whispered to surpass even his older brothers'—to see it bloom as quickly as possible and claim the recognition he craved. And so, on the morning of his third day in isolation, Deleve checked the timetable pinned to his wall, confirmed that the elective instructor had a class scheduled for today, and strode out of the dormitory.
I'll figure it out in today's class.
He hadn't intended to follow the man from the start. It was purely by chance that he spotted Xiel near Elbat Hall, but once he did, his feet moved on their own.
"Why... why is it blocked?"
Deleve came to an abrupt halt before a dead end. Today was his first time setting foot in Elbat Hall, so he wasn't familiar with the layout, but structurally speaking, there was no reason a dead end should exist here. What was worse, the elective instructor had vanished without a trace.
"Is there another path?"
From the opposite side of the corridor, Xiel watched Deleve tilting his head in utter bewilderment.
Different from an ordinary tail.
Every tracker Xiel had encountered in the past would turn back, search for another route, or take evasive measures the moment they lost visual contact. Yet this boy simply stood there.
Does he have an ulterior motive?
Why was Deleve Kundel trailing him?
Does he have business with me, like Student Celia Rihardt?
That seemed the most plausible conclusion. Or perhaps it was some sort of passing fad among the student body.
Stalking one's instructor. How peculiar. Then again, the pre-mission briefing never covered such trends.
The world was vast, and customs varied wildly. If he wished to remain at Edelbein Academy long enough to secure a full professorship, he needed to adapt to these eccentricities as quickly as possible.
"Student Deleve Kundel."
Deleve jumped out of his skin at the sudden voice behind him and whipped around. His heart leaped into his throat. The instructor who had just vanished into thin air was standing right behind his back.
"I-I-Instructor? When did you—"
"You were tailing me."
"..."
He was caught.
Was I too obvious?
If he had known this would happen, he would have just walked quietly into the classroom like everyone else.
"Is it a trend?"
"Pardon?"
"I asked if it is a trend among the students."
"A... trend?" Deleve blinked, unable to comprehend the question.
"Following in your instructor's footsteps."
"...I-I wouldn't know."
"If it is a trend, you should practice doing it more naturally. Ducking behind a tree or peeking only your head out makes your presence excessively conspicuous. When possible, it is preferable to blend into a crowd while tracking a target, or take to the rooftops where their field of vision is least likely to reach."
Deleve stood slack-jawed at the sudden lecture on espionage tradecraft.
Why would that ever be a trend?! And why are you explaining it in such terrifying detail...?!
"Try to be more proficient during your next tail."
"Ah... well..."
Xiel pulled out a silver pocket watch, checked the time, and turned away.
"Class begins in five minutes. Take care, as tardiness incurs demerits."
"R-Right. Yes, sir."
"Carry on."
Rounding the corner Deleve had just pursued him past, Xiel vanished from sight. Deleve stared blankly at the empty hallway, the original purpose of his pursuit wiped entirely from his mind. Then, on pure instinct, he glanced behind him—and his knees gave out, sending him sprawling to the floor.
"Wh-What the hell?"
The corridor he had sworn was a dead end stretched out completely open. Down the hall, he could even see students leisurely filing out of their lecture rooms.
"Crazy bastard..."
Rattle.
Having taken a minute to recover from the shock, Deleve entered the training hall sixty seconds late.
"You are late, Student Deleve Kundel. That is one count of tardiness."
Whispers broke out among the gathered students at the sight of him.
"What's with his face?"
"Haven't you heard? Word is he got completely demolished by that instructor in their first elective."
"Oh, the self-defense class?"
Deleve's shoulders twitched. Just as he was about to glare over his shoulder, a flat voice cut through the air.
"I believe I stated the rules before class began. You two students, what are your names?"
"Instructor, we weren't talking—"
"I heard you clearly. State your names."
"...Karen Aswan, sir."
"Luke Miole..."
Cornered by his unyielding gaze, the two had no choice but to confess.
"Student Karen Aswan, Student Luke Miole. Both of you receive a warning for idle chatter. Take note that this will be reflected in your final evaluation."
"Ah, Instructor!"
"This class proceeds strictly by the book."
Scribble, scratch.
The sound of Xiel's pen scratching against parchment echoed through the room as he methodically jotted down their names. The students swallowed their protests, and a heavy silence descended over the lecture hall.
Deleve watched the scene with a strange, conflicted expression.
Was he... looking out for me?
"And Student Deleve Kundel. As you were late, that will likewise be reflected in your grade."
Of course not.
Just what is his deal? What kind of backing does he have to be this brazen?
From the side, Celia Rihardt observed Xiel with narrowing eyes, her curiosity burning just as fiercely. No matter how she looked at it, he had to have a powerful patron. An ordinary elective instructor wouldn't dare act so imperiously toward scions of the empire's greatest bloodlines unless he held an ironclad card up his sleeve.
There's definitely something behind him.
As names of influential noble factions raced through Celia's mind, Xiel formally began the lesson.
"Today's class is Healthy Body and Physical Strength."
True to its title, it was an elective meant to teach the theory of the physical vessel and build foundational stamina. Alongside self-defense, it was a curriculum centered entirely on physical conditioning, tailored specifically for the Sword School.
I brought my sword, so who should I spar with?
Guess I'll just practice my forms by myself.
Naturally, that was merely how the syllabus read on paper; historically, the course had never once been run according to design. Students usually sparred, swung their blades at their own pace, or simply lazed around as they pleased. The teaching assistants sent to fill in for the chronically absent instructor had gladly looked the other way. They were swamped with work as it was, so an unsupervised free period suited everyone.
Xiel, however, was an entirely different beast.
"Before commencing full-scale conditioning, we will measure your individual fitness levels."
A sudden hush fell over the hall.
A fitness test!
"Um... Instructor." A hand went up.
"Student Karen Aswan. Do you have a question?"
"What exactly do you mean by measuring our fitness levels?"
"Precisely what is stated in the course syllabus. I intend to evaluate the baseline physical endurance of the first-year Sword School students gathered here, then prescribe customized conditioning regimens tailored to those measurements."
"Right... so, what is the actual method of measurement?"
Even then, Karen and the rest of the class clung to a sliver of hope. They thought he might simply observe them sparring or running through drills to gauge their stamina. The upperclassmen had sworn that this elective was pure leisure, a guaranteed high grade for zero effort. Lately, those who hadn't enrolled had even been mocking them—claiming they'd tried to take the easy way out, only to land themselves in hell.
Out of the class of one hundred freshmen, forty had enrolled, believing they were the fortunate few. In truth, they had stepped straight into a pit of thorns.
'Heard you went hunting for an easy ride, only to run into an absolute monster of an instructor.'
'Have fun suffering. I'm off to Professor Elcanto's lecture.'
'Professor Elcanto's elective has to be ten times better than that mess, doesn't it?'
"Long-distance running," Xiel answered flatly.
A collective sigh of relief subtly rippled through the room. Long-distance running? A few students even smirked behind their hands. Every student here had earned their place in the Sword School to master the blade and martial arts. Naturally, they had received rigorous physical conditioning within their respective families long before entering the academy, clawing through cutthroat competition to get here. If there was one thing none of them lacked, it was physical endurance.
Or so they believed.
"How many laps?" someone called out.
"As many as possible."
"Doesn't sound like much."
When one student chuckled derisively, several snickers followed in agreement. But the amusement died the instant Xiel reached into a crate and lifted an object into view.
"Sandbags. You will run wearing these."
Sandbags.
It was such an archaic training tool that none of them had anticipated seeing it here. Most of these highborn students had only ever seen them gathering dust in armory basements or strapped to common foot soldiers during outdated garrison drills.
That's nothing.
Hah, easy enough once we circulate mana.
The instructions that followed immediately shattered their complacency.
"The use of mana is strictly forbidden."
"Pardon?!"
"It is a matter of course. If you augment your output with mana, your pure physical endurance will not experience dramatic improvement."
Stunned into absolute silence, the students stared at him in disbelief.
"The syllabus provided to me specifies 'the most appropriate method.' Long-distance running remains the most effective exercise for evaluating an individual's innate physical reserves."
They understood the theory, but running with sandbags without a shred of mana enhancement?!
Xiel pointed toward the far end of the vast gymnasium.
"Strip off all excess gear and line up at the perimeter. At my signal, you will circle this hall."
"U-Until when, sir?"
"Until you are exhausted."
"If you say until exhausted..."
"You will run until all physical stamina is entirely depleted and your muscle fibers no longer respond."
"What if we simply lose the will to keep going?"
"The criterion for halting is not your willpower, but the physiological limit I just defined. That is all. Move to your positions."
Without another word, Xiel picked up a pair of heavy sandbags and strapped them around his own ankles. Watching him prepare to run alongside them, the students froze in mounting disbelief.
To Xiel, this was nothing out of the ordinary.
During my first two years, all I did was run.
That had been the baseline of assassin indoctrination. And the weights he had worn back then were far heavier than these.
"H-Hey... are we really doing this?"
"H-He said to..."
"No, that's insane—"
Before the murmurs could spread, one student stepped forward in silence. Unbuckling his sword belt, he laid his rapier gently on the floor, walked over to the crate beside Xiel, and picked up two sandbags. He strapped them firmly around his ankles.
Thud. Thud.
Stepping out of the ranks, he marched directly to the starting line at the edge of the hall.
It was Deleve Kundel.
The remaining students flinched at the sight. And then, another silhouette moved.
"C-Celia too...?"
Celia Rihardt followed suit, tossing aside her scabbard and strapping the weights onto her boots without a word of complaint.
Kundel and Rihardt. With the scions of the two premier houses taking the lead, the rest of the students reluctantly fell into line, strapping on sandbags and assembling along the perimeter.
"Begin running."
At Xiel's signal, forty students pushed off the floor.
Run until we drop dead?
I have a core lecture later today, I'm going to lose my mind...
Yet not a single student dared grumble aloud. Because right beside them...
"Maintain a regular breathing rhythm. Do not draw breaths too shallowly or drag them out excessively; keep your respiration under strict, steady control."
Xiel was pacing them stride for stride, his voice utterly level and tranquil as he ran.
"Student, land lightly on your arches. Striking the heel like that will damage your knees in short order."
"Y-Yes, sir!"
"Student Karen Aswan. Do not force yourself to match the pace ahead of you. It is vital to run at a tempo your body can sustain."
He offered precise, unhurried corrections to anyone whose form slipped. At first, they thought they could weather it. But by the tenth lap, the strain began to tell.
Stragglers fell off one by one, and even those maintaining the lead began panting with ragged breaths. The sandbags. The complete ban on mana. The weights were suffocatingly heavy, dragging at their calves as though unseen hands were pulling them down into the floorboards.
"Eyes forward, not on the ground. Looking down will tangle your footing."
Xiel’s voice remained impossibly serene. When the first drop-out finally collapsed against the wall, Xiel maintained his stride, veering over to the fallen boy without breaking rhythm.
"Your name, student?"
"Haa... haa... Yulio... haa... Harmatan, sir."
"Yulio Harmatan. Twenty laps."
The frail, slight-framed Yulio managed a faint nod from the floor. From then on, every time a student crumpled in exhaustion, Xiel appeared at their side like a shadow, asking their name and logging their score with absolute precision.
How does he keep track of everyone?
Forty students were running at wildly different intervals. Yet he remembered every single lap count without glancing at a ledger, announcing each total before seamlessly returning to the front of the pack. What was truly terrifying was that he wasn't out of breath in the slightest. Despite wearing sandbags himself, not a single bead of sweat had formed on his brow.
Is he a monster?
Is he really just an elective instructor? Seriously?
Their initial skepticism curdled into pure dread. They had crossed someone they never should have provoked.
Why did this have to happen in our freshman year...?
The seniors swore electives were an easy pass!
Roughly thirty minutes passed. To the absolute disgrace of the Sword School's reputation, nearly half the class had collapsed. Had they been permitted to circulate mana, every single one of them could have effortlessly run dozens more laps. But stripped of their internal reinforcement, they dropped like flies.
Every student admitted to the Sword School had awakened to mana. Whether novice or prodigy, they were accustomed to channeling mana through their meridians to endlessly bolster their physical limits. Denied that crutch, their raw physical bodies gave out in record time.
Naturally, not everyone had the integrity to run strictly by the rules.
Patter.
Picking up his pace slightly, Xiel drew up alongside the student leading the pack. Unaware that the instructor was right beside him, the boy glanced around, his eyes narrowing in calculation.
Just a little bit. Just a tiny sliver. He'll never notice. It's not like he's a master mage.
"You used mana."
"Gah?!"
The student nearly leaped out of his skin at the voice whispering right beside his ear.
Xiel had been an assassin until mere days ago. In fact, he had been the greatest reaper the underworld possessed—the legendary 'Phantom,' feared by kings and corrupt syndicates alike. The reason other assassins could never match him, the reason he had completed impossible missions and returned unscathed, lay in his sensory perception. His energy awareness was beyond perfection.
"What is your name, student?"
"I, uh... that is..."
"You just circulated mana."
"Uh... w-well... you see..."
Completely rattled, the boy stammered, unable to string a sentence together. The remaining runners and the dozens sprawled across the floor watched the scene unfold with bated breath.
"I asked for your name."
Xiel spoke without a trace of fatigue, his flat, even tone only magnifying the oppressive weight of his presence.
"M-Maris Sophen, sir."
"Student Maris Sophen. Remove yourself from the track immediately. Stand over there against the wall until the end of the period."
"..."
"Did you not hear me?"
"Wh-Where is your proof that I used mana?!"
Xiel tilted his head slightly. "Are you asserting that you did not?"
"..."
"Eighty-five laps. However, as you utilized mana, your record is voided."
Though delivered with absolute detachment, the words struck Maris with such chilling weight that he would have preferred being shouted at.
"Voided?! That's unfair!"
"If you truly did not use mana, report to this exact spot at this time tomorrow and run under the same constraints. If you match your current lap count in the same state without issue, I will officially recognize your record."
"..."
Maris could not utter a single word of rebuttal. Inwardly, however, he was grinding his teeth so hard they threatened to splinter.
Who does a pathetic elective instructor think he is...?!
"You are obstructing the class. Step aside."
In the end, Maris was forced to peel away from the track. Yet as he walked to the wall, his entire frame shook with humiliation.
Humiliating me in front of everyone just for channeling a little mana?!
Maris Sophen was the eldest son of House Sophen, a family positioned immediately below the Five Great Families. While he might not hold the terrifying pedigree of Deleve Kundel or Celia Rihardt, he had drawn significant attention from the Sword School's faculty during admissions.
A worthless contract teacher dares to treat me like this...?
Meanwhile, watching Maris slink toward the wall, an identical thought crossed the minds of every surviving student:
How on earth did he notice?
Only high-tier knights capable of Mana Manifestation—projecting their internal energy outward to coat a blade or a fist—produced visible mana that could be seen with the naked eye. Merely activating internal mana within one's own muscle fibers was notoriously difficult for an outside observer to discern.
Maris, you complete idiot, getting caught like that.
Did he really think he could make it that obvious? Does he think the rest of us are running like this because we're stupid?
Naturally, the students assumed Maris had simply botched his control. None of them suspected that Xiel had caught the microscopic fluctuation using the supernatural senses of a legendary assassin.
Another thirty minutes bled away.
"Haa... haa..."
"Huu... huu..."
The vast gymnasium was filled with nothing but ragged, tearing gasps and the dull slapping of boots against wood. Only two students remained on their feet.
Strapped with sandbags. Forbidden from using mana. The fact that they were still moving under such conditions was nothing short of monstrous.
"H-Hey... who do you think's going to win?"
"Isn't it obvious?"
Deleve Kundel. Celia Rihardt.
As fate would have it, only the scions of the two ducal houses currently locked in a bitter political rivalry were left standing. And through it all, Xiel continued to run alongside them, pacing their strides without shedding a single drop of sweat.
"Even with mana, running like that without tiring should be impossible..." Karen Aswan muttered in a daze from the sidelines.
Ten more minutes passed. It was a war of attrition that no one could interrupt, a contest of pure stubbornness where neither would allow the other to claim victory.
Thud!
Five minutes later, one of them finally broke.
Or rather—the moment the boy began to pitch forward—
"Student Deleve Kundel."
Xiel closed the distance in a blur, effortlessly catching the collapsing boy by the shoulders to steady him.
"Two hundred and twenty-five laps."