An assassin knows the body the way a scholar knows a map. The precise coordinates of the heart, lungs, liver, kidneys. The count of bones. The distribution of muscle, the mechanics of organs, the hidden architecture beneath the skin—what does what, and why. To understand that is to understand where to strike, where to sever, and more importantly, what happens after.
Which is why, when Yurio Harmattan’s pulse finally steadied—only slightly, reluctantly—Ziel spoke.
“Student Yurio Harmattan,” he said in a voice that allowed no room for debate, “run for me. A short distance. From here to here.”
Yurio jolted. “Huh? Ah—yes, yes sir!”
It was no ordinary observation. Ziel did not merely watch. He dissected motion itself. The shift of tendon under skin. The shiver of cartilage. The cadence of breath. Even the trembling resonance of Yurio’s heartbeat.
Irregular.
His verdict came swiftly, quietly, internally—as lethal diagnoses often did.
Mana flow stagnated. Constricted in places. Blocked in others. Muscle response went jagged, breathing unstable. The largest bottleneck— The heart.
A fluctuation in pulse meant strain at the core. If the mana circuit jittered there, the myocardium itself was likely affected.
Another instructor might have wondered how a student like that survived entrance into a sword academy. But not Ziel. He never wasted energy on why the world was flawed when he could be thinking about how to fix it.
“Haah… haaah…”
“That’s enough, Yurio Harmattan. Return.”
Before Yurio had even fully straightened, Ziel’s hand was already rising—pressing directly over his chest.
“S-S-Sir…?”
“Stay still.”
A few meters away, the others had slowed to a jog, then a walk, then a gawking standstill.
“Haaah—what is he doing?”
“No clue—oi, look over there!”
“Still, he’s lasting longer than last week, right? Kinda feels like his stamina’s improving!”
Only Dellev watched in tense silence—too tense.
“Jealous?” someone snickered.
“J-Jealous? Of what?”
“You haven’t blinked once, man.”
“Shut—shut up!”
He broke into a sprint to escape the accusation, yet Celia remained staring too, unable to look away either.
What could possibly take that long?
Unlike Dellev, though, her thoughts drifted elsewhere.
When should I ask him to be my escort knight?
It was, in her mind, a matter of when, not if.
Meanwhile, Yurio’s face pinched tight.
“Sir… my chest feels… really warm…”
“I am locating the blockage. It may feel unpleasant.”
“It—may also feel like it hurts!”
“Endure it.”
From afar, the scene looked bizarre enough that several students exchanged sideways glances.
And then, with clinical calm—
“Left atrium, lower by three centimeters. Right atrium, upper by two. Both in regions tied to mana-blood circulation.”
Yurio’s jaw dropped.
“Wh—What does that even mean?”
“It means,” Ziel said simply, “there was always a reason your stamina lagged. Since when?”
“Since… since I was born. But—how did you know?”
“I infused mana into you.”
Silence.
Because that technique—was not medicine. It was assassination.
A method used when weapons were absent, when silence mattered more than blood. Slip mana into the target’s system. Trigger disruption. Cripple. Neutralize. Or, if necessary… detonate it from within.
One of the reasons Ziel had once been called the Wraith.
Yurio stared as though the ground had learned to speak.
Mana infusion… inside a person? That’s possible?
Before he could spiral further, Ziel asked, “Which breathing method were you taught?”
“Oh. Uh…” Yurio fumbled, ears flushing. “It was… one my father acquired. It was very expensive…”
“Perform it.”
And as though spellbound, Yurio sat, inhaled, and began cycling mana through the familiar pattern.
Ziel laid his palm back over his sternum, tracing the flow with cold precision.
The verdict arrived, devoid of hesitation.
“This breathing method does not suit Yurio Harmattan.”
Yurio went rigid. “What?”
“I will revise it.”
“…Revise? Sir—modifying a breathing method is incredibly dangero—”
“I know. I will succeed.”
“…Sir?”
Once a mana breathing technique is ingrained, adjusting it is akin to rewriting instinct. Most swordsmen spend a lifetime making marginal refinements. Tiny ones. Safe ones.
Changing it outright?
Impossible.
Unless you were Ziel.
“It cannot be impossible,” he said flatly, “because I will do it.”
Yurio could only stare, mind blank, logic trailing hopelessly behind.
Because mana breathing methods are not just routines—they are architecture. Delicate. Purpose-built. Individual-coded. A single misalignment could destroy a path instead of forging it.
Which is why noble houses guard techniques like crown jewels. Which is why warriors whisper: Your first breathing method decides your ceiling.
Ziel wasn’t proposing replacement. Only correction. A reordering of current pathways, not demolition and rebuild.
“Your mana’s route conflicts with your body’s condition,” he explained. “Especially here—your heart requires priority, yet your method starves it.”
Yurio could barely speak.
“How could you even know that?”
Ziel didn’t answer.
He simply placed two fingers over the point where mana throbbed unevenly—like a faulty gear grinding against fate—and allowed silence to sharpen into awe.
Yurio had never known an easy breath.
Even as a child, his heart carried a weight—tight, congested, wrong—as though every beat had to squeeze its way through a place it did not quite fit. That was why, when selecting a breathing method, he had been painstakingly careful. His heart could not afford strain.
And yet—
“You’re saying… you can change it?”
“I can,” Ziel replied, eyes unblinking, tone matter-of-fact. “Right now, your mana path grazes the heart only once per cycle, and at a distance. I’ll redirect it. Instead of passing by as an afterthought, it will brush the nearest artery twice.”
He wasn’t proposing to demolish the entire structure of Yurio’s breathing method. No. It was more like changing the route of a road—not carving a new highway, but replacing a wide detour with a tighter, more efficient shortcut that still connected to the original system.
On paper, it should have sounded simple.
In reality?
“…That’s terrifying,” Yurio whispered.
“Terrifying?” Ziel echoed, tilting his head. “Then this doubles as a lesson in conquering fear.”
Yurio physically shivered.
What if it fails? What if I break completely? What if the weakness I was born with finally collapses me for good?
“I’m… actually really scared, sir…”
A quiet breath. Then—
“Believe me, Yurio Harmattan. You are capable.”
“But… no one has ever said anything like this to me before…”
“Then do you stop here?” Ziel asked.
Silence.
“If you stop here,” Ziel continued, voice as certain as an unsheathed blade, “you will live your entire life with mediocre stamina. Or worse.” He leaned just enough that his gaze pinned Yurio in place. “Do you not wish to conquer fear?”
Something inside Yurio cracked open—not loud, not explosive, but deep.
Fear of collapse. Fear of being insufficient. Fear of being the frail disappointment in a family that needed strength.
In the middle of it all, in all his years of training, in all his quiet shame—only one person had ever praised him.
And it was this man.
“…You really think it’ll work?” Yurio asked, voice thin.
“A teacher does not lie to his student.”
Still trembling, Yurio nodded.
“…Then I’ll do it.”
The words landed like a vow.
It was insanity. It was impossible. Breathing techniques were not edited like drafts—they were carved like bone. Modifying one was a gamble no rational swordsman would ever take.
But—
Mr. Ziel said he can.
And Yurio believed him.
Ziel, watching the shift in the boy’s face, studied it with clinical curiosity.
His eyes have changed. Is this emotion? Was that fear, earlier?
He was only just beginning to understand what feelings looked like.
“Breathe, Yurio Harmattan. When I instruct, change direction. I will guide you.”
Yurio didn’t understand the mechanics. Not yet.
But he felt it immediately.
Warmth.
Ziel’s mana threaded into his like a guiding hand, gentle but precise, helping his breath turn where it had never turned before.
Ziel himself was surprised. He’d used mana insertion countless times to sabotage bodies, hijack circulation, collapse organs from the inside out.
He had never used it to heal.
So it works like this as well, he thought.
Ziel was the only assassin in his order to master Breath of Long Night, a technique that let him read mana currents in people, air, even enclosed chambers. It was how he’d eliminated targets thought untouchable—
A noble guarded by fifty knights. A slave-trader hidden in a locked vault. A high priest who’d prepared traps in his name.
All died cleanly, quietly, impossibly.
Only now, far from that world, did he realize the truth.
His talent was never for killing.
It was for understanding the flow of life itself.
“Now. Slightly left.”
“Hhh—”
“Good. Right. A bit upward.”
He guided like a blacksmith shaping molten iron, firm, precise.
The new route was foreign, painful, burning.
“Ng—!”
“Hold your posture, Yurio Harmattan.”
“I—It’s really painful, sir!”
“There is pain suppressant,” Ziel offered. “But numbing the senses will make the redirection imprecise.”
Why does this man carry pain suppressants? Yurio wondered furiously.
“Then… endure.”
Yurio clenched his teeth so hard his jaw shook.
He still didn’t fully believe it.
I lived with this for over a decade. Can one night really change that?
“One last cycle,” Ziel said.
Yurio exhaled—shaking—then inhaled, drawing mana along the path Ziel carved for him.
When he finished, he collapsed face-down on the ground.
“Hah… hah…”
“Remember that path. That is now your circulation,” Ziel said. “How do you feel?”
“Tired,” Yurio wheezed.
“No abnormalities. Continue.”
Again. Then again. Five cycles in total.
By the third, the pain dulled.
By the fourth, breathing felt different.
By the fifth—
“Huh?” Yurio blinked.
His chest felt… light.
The constant pressure he’d carried for as long as he could remember— the invisible hand gripping his heart— was loosening.
“Your left and right atrium pathways have widened,” Ziel observed. “Mana and blood flow are stabilizing.”
Could that really be true?
—A teacher does not lie to his student.
Ziel’s earlier words returned with quiet gravity.
By the fifth cycle, Yurio’s breath came easier—cleaner—freer.
“…Sir…” His voice cracked. “…Is this actually…?”
“Yes. Running should no longer feel unfair,” Ziel said simply. “You are closer to even ground now.”
“Sir…”
Emotion surged up faster than Yurio could fend it off. He dropped into a bow so fast it was almost violent.
Tears hit the dirt.
Someone finally praised me. And then… he fixed me?
It was absurd.
It was impossible.
It was real.
Who… who even is this man?
No one should be able to rewrite a breathing technique mid-lesson. No one should be able to heal a congenital defect by reshaping mana paths with bare hands.
And yet.
Here, now, someone had.
This was something only Ziel could have done.
Altering another person’s breathing method—adjusting the path itself rather than rebuilding it—was not merely unconventional. It bordered on impossible. For Yurio, it had already passed beyond reason and landed squarely in the territory of miracles.
“One last time,” Ziel said. “Try it again.”
“Yes, sir!”
Yurio’s voice carried a strength it had never had before. He steadied himself, assumed the posture, and drove his mana forward in a full circuit.
The difference was immediate. Smoother. Lighter. Less like dragging his heart along behind him.
And yet Ziel wasn’t finished.
“Pause. Route the mana through the heart twice per breath.”
Yurio’s head snapped up. “Twice?! That goes outside the method entirely!”
“It is possible. Attempt it. I will guide the current.”
Ziel looked, for the first time, faintly intrigued—like someone who had just solved a puzzle without realizing he’d been solving one.
This configuration suits Yurio Harmattan’s body better.
Yurio’s heart was weaker than most. Congenital vulnerability compounded by a breathing method that had never actually fit him—like wearing boots a size too small for a decade and calling the blisters inevitable.
The solution wasn’t brute force.
It was alignment.
You know what? Yurio thought, exasperated and half-hysterical. I’m not even going to try to understand anymore.
Understanding only made his head hurt.
At a certain point—
It’s just Mr. Ziel.
So he breathed.
Once.
Twice.
His heart spasmed against the strain—but Ziel guided his mana like a steady hand on a frightened animal, firm and sure. Again, Yurio forced the cycle, gritting his teeth, nearly shaking—
And then.
It clicked.
Mana looped twice around his heart before completing its route.
“Success,” Ziel declared.
“Sir…” Yurio exhaled, nearly reverent.
“Maintain it. Lock it into memory.”
“Yes, sir!”
It wasn’t that the Breath of Long Night enabled this feat. It was that a man capable of this feat was always destined to master the Breath of Long Night.
His talent for sensing, shaping, redirecting mana—whether in bodies, air, or architecture—was staggering. It had made him a ghost in the dark, an impossible killer.
Now, without even noticing the moment it happened, that same talent was saving a life instead of ending one.
He’s incredible… truly… Yurio thought, genuinely awed.
In that moment, something stirred deep and unstoppable in him— the sprouts of hero worship.
He could keep up now. He wasn’t dead weight anymore. For the first time, the future looked like something approachable instead of something to fear.
Ziel straightened. “Your breathing method has been adjusted. No irregularities. Run.”
Yurio nearly bowed mid-sprint. “Yes, sir! Thank you, sir! Truly—thank you!”
The volume alone made several students flinch.
Then they saw him running.
“Wait—what?”
“Since when can Yurio sprint like that?!”
“I thought the guy had lung issues?!”
“Maybe adrenaline? Or a second wind?”
“More like a sixth wind!”
Yurio’s previous record had been twenty laps. Today, thirty—and total collapse. But now? He’d hit fifty… and was still going.
“Fifty laps? Fifty?! How is he still upright?!”
“What did Sir Ziel do to him?”
“This doesn’t even make sense!”
Karen gaped, calling after him, breathless.
“Yurio! What happened to you?!”
“No idea! Gotta go! Later, Karen!”
Ziel watched it all with unreadable calm.
Was it the gratitude? Was it the student’s improvement?
Ziel couldn’t quite identify the cause—but his mouth had curved upward by a single, almost imperceptible degree.
When Yurio finally staggered to a stop, he had run sixty laps.
Sixty.
It was still below academy average—but for someone once considered borderline unfit for combat school, it was nothing short of transformation.
“Sir—hah—my stamina—hah—”
“It improved,” Ziel finished for him.
“Thank—hah—you— sir!”
Yurio sat, gasping, but there was something brighter threaded through each breath now. Relief. Disbelief. Hope.
He mentioned having an illness, Ziel recalled, overhearing a fragment of Yurio and Karen’s earlier conversation.
He had treated the symptoms—but not the source.
Perhaps I should find that back-alley physician. If he’s still alive, that is.
But for now, class was waiting.
Ziel turned, voice carrying effortlessly across the training field.
“Class dismissed. Gather.”
Cliche Novel 