The night was quiet, a pale moon hanging over the forest. Toji crouched high in the branches of an ancient cedar, one hand resting casually on the hilt of the Split Soul Katana. His emerald eyes scanned the path below with the focus of a predator.
Earlier that day, he had overheard farmers gossiping in a tea house. A small patrol of Demon Slayers had passed through, boasting of Breathing Styles—special techniques that sharpened body and blade against demons. Toji had feigned disinterest, sipping his tea in silence. But his mind sharpened immediately.
A technique that could make him stronger? That was worth seeing.
Now he watched.
Below, three young Slayers in plain uniforms patrolled the road. Their swords were Nichirin, their posture rigid with training. Two moved with confidence, their lungs rising and falling in a steady rhythm that hinted at controlled breathing. The third lagged behind, clumsy and tense, swinging his blade too wide, his steps unrefined.
So that's the difference, Toji thought, smirking faintly. Two with technique. One without. A system that separates the weak from the useful. Reminds me of the Zen'in clan.
The thought tugged something bitter in his chest, but he buried it with a lazy grin.
The Slayers stopped. The air shifted. From the underbrush came the low hiss of a demon—hungry, frantic. Its eyes glowed red as it lunged at the weakest Slayer.
Toji's fingers twitched on the hilt of his katana. Instinct told him to cut it down instantly. But instead, he watched.
The stronger of the two Slayers surged forward, blade flashing. He inhaled deeply, his chest expanding unnaturally, and then exhaled with a shout:
"Water Breathing, First Form: Water Surface Slash!"
The blade moved fluidly, glowing faintly in the moonlight as it cleaved through the demon's arm. The creature shrieked, stumbling back, surprised by the force of the blow.
Toji's eyes narrowed, studying every detail. The rhythm of the Slayer's lungs. The tightening of his muscles. The way his movements sharpened when tied to his breathing.
So that's Breathing, huh? Enhances strength, speed, maybe even focus. Not bad.
The other skilled Slayer followed up with a thrust, finishing the demon in an efficient strike. Ash scattered on the breeze. The clumsy third stared in awe, clearly too untrained to contribute.
Toji leaned back against the branch, his smirk widening.
"Interesting. So this world teaches tricks to make up for what they lack."
But beneath his amusement, his mind calculated coldly. If Breathing could amplify a normal human to kill demons… then what would happen if someone like him—whose body already surpassed human limits—used it?
The thought made his pulse quicken, just slightly.
---
The Slayers moved on, oblivious to the predator in the trees. Toji dropped silently from the branch, landing without a sound. His blade remained sheathed.
"I'll need to see more," he muttered, voice calm but tinged with curiosity. "If I can steal their little tricks, maybe I'll carve out a place in this world worth my time."
His smirk deepened, wolfish.
"And if not… at least the fights will be fun."
With that, he vanished into the night, like a ghost.
---
Muzan's crimson eyes opened in the gloom of his mansion. He had seen the fragments of Mukagoji's final moments — the blur of steel, the suffocating pressure of a man's presence, and death that came too swiftly for a Lower Rank to resist.
His lips curved, though the smile carried no warmth.
"…A Slayer. But not one I know."
He rose, his pale form gliding across the floor with elegance that belied the malice in his aura.
"He carried no uniform. No crow. No mark of the Corps. And yet… he cut down one of mine."
Turning sharply, Muzan's voice hardened like steel.
"Akaza."
The Upper Rank appeared instantly, kneeling with head bowed. "Yes, Muzan-sama."
"There is a man out there — nameless, without affiliation — who has slain a demon as though it were nothing. Whether he wields a hidden Breathing Style or some other technique, I do not care. Find him. Test him. If he survives…" Muzan's smile sharpened into cruelty, "…then bring him to me."
Akaza's eyes gleamed with anticipation. "Understood."