Kagerou laid Kyojuro gently onto his futon, brushing the boy's hair back before pulling the blanket over him. He lingered for a moment, watching his brother's peaceful face. A sigh slipped from his lips before he quietly slid the door shut behind him.
The hallway stretched ahead, dimly lit by lanterns swaying faintly with the night breeze. As he passed the room where Ruka labored, the muffled sound of the midwife's instructions and Ruka's heavy breathing reached him. Each strained cry stabbed into Kagerou's chest, sharp and merciless, as though someone were tearing him apart from the inside. He could endure wounds, bruises, exhaustion but this… this helplessness was agony.
In front of the door, Shinjuro stood like a man carved from stone, face twisted with pain as if the labor were his own burden to bear. Hearing footsteps, he raised his head, eyes locking on Kagerou.
"Kage… where are you going?" His voice was hoarse, almost breaking.
"To keep my mind calm," Kagerou replied curtly, his tone clipped but steady. He didn't stop, only walked past.
Shinjuro clenched his jaw, watching his son's small back retreating further into the shadows of the house.
'Too calm for a boy of his age,' he thought bitterly. 'Too mature for his own good'
"…You're strong, Kage. Not like me," Shinjuro muttered under his breath.
Kagerou slid open the engawa door and stepped out into the cool night. He bent down, retrieving his kiseru where it had fallen earlier. From his sleeve, he drew the pouch of foreign tobacco, packed the bowl, and lit it with practiced hands. The flame's glow briefly lit his face before vanishing into the darkness.
He looked out at the yard, the place he had carved his body into steel through endless training. Tonight, under the pale moonlight, it would serve another purpose.
Kagerou steadied his breathing, the pipe pressed to his lips. The smoke curled into his lungs, and then...
"…Kemuri no Kokyū… Ichi no kata: Kon'en (Soul Mist)"
When he exhaled, it wasn't only from his mouth. Smoke seeped from every pore of his body, rising, coiling, expanding outward. Within moments, the yard was blanketed in a thick, ghostly fog, the moonlight fractured and scattered through the veil.
#A/N: "This is the reason that in this fic, I picture the Demon Slayer as a Semi-Elementalist"
Kagerou's figure blurred within the haze, like a shadow becoming one with the mist itself.
"…Kemuri no Kokyū… Ni no kata: Enpo (Smoke Step)"
*...Step*
The sound was soft, yet it echoed strangely inside the fog. His body shimmered, half-solid, half-phantom, until he seemed to dissolve into the mist itself, leaving behind nothing but smoke swirling gently where he had once stood.
Deep inside the rolling mist, Kagerou slipped a hand into his haori. His fingers closed around the hilt of a six-inch tanto. With a soft *shhkt* he drew the blade free, its faint gleam swallowed almost instantly by the smoke.
He shut his eyes.
The world shifted.
Every breath, every pulse of life inside the haze sharpened. The chirp of crickets, the faint rustle of moth wings, even the tremor of a beetle's legs crawling over bark, each sound came alive in perfect clarity. Within the mist, nothing escaped him.
His grip tightened. His lungs expanded. Then...
"…Kemuri no Kokyū… San no kata: Fukuei (Shrouded Shadow)
*Ksshh!*
Kagerou's body blurred the instant his foot touched the ground. His form darted forward in sharp, jagged lines, every movement concealed by coiling smoke that twisted violently around him. His tanto gleamed once under the moonlight, then vanished, swallowed whole by the haze.
The smoke obeyed him, each slash pulling long ribbons of mist through the air, shaping vague human outlines that darted and split apart. They flickered like distorted shadows on a burning wall, here, then gone, then suddenly right behind you.
From the outside, it was impossible to tell where Kagerou truly was. Six, seven, eight silhouettes tore through the fog, each moving in a zigzag, each raising a blade at a slightly different angle. But only one carried the weight of death.
*Swish!* *Swish!* *Swish!*
The insects hiding in the yard never stood a chance. Mosquitoes sliced mid-flight. Moths shredded into drifting wings. Beetles cracked in two, their shells falling like pebbles against the wood. Even the faint hum of gnats winked out in silence. One by one, each sound in the mist was severed until the night itself grew hollow.
The air was heavy with the scent of smoke and cut grass, the fog trembling as if alive.
Kagerou reappeared for a heartbeat, gray eyes sharp, before fading again, his outline melting back into the haze.
In that suffocating white shroud, boy and mist became one. What remained was not a child, but a phantom hunter cloaked in shifting haze, striking so fast that reality itself struggled to keep pace.
Kagerou's gray eyes narrowed. The insects were gone, but his breath still burned in his chest. 'If there's no target… then I'll make one'
He closed his eyes. The world went silent except for the steady pull of air through his lungs. In his mind, a demon towered before him, fangs bared, claws dripping with hunger. His heart steadied, breath sharpened.
"…Kemuri no Kokyū… Shi no kata: Genbu (Phantom Dance)"
*Step…*
His foot touched down lightly, and the yard transformed. Smoke swirled as though alive, curling into flowing shapes that twisted around his body. With a graceful pivot, Kagerou's form split into two, then four, then eight.
Each afterimage moved with him, not as clumsy echoes, but as perfect reflections. The mist sculpted them into swordsmen with blades gleaming pale like ghosts under moonlight. Every slash he made was answered by a chorus of phantoms, their steel singing in perfect rhythm with his.
*Clash!* *swish* *clash!*
The dance unfolded like a waltz, steps weaving in smooth, seamless arcs. His haori fluttered through the fog as he spun, tanto flashing, each movement mirrored by the smoke-born doubles. The illusions attacked from every side: left, right, above, behind.
To an enemy, it would be suffocating. A dozen killers advancing in harmony, cutting with the same merciless elegance. Their strikes blurred the line between reality and dream; one could no longer tell where the real Kagerou stood, nor which blade would draw blood.
The haze carried the rhythm of battle itself, every pivot pulled new shadows from the fog, every swing carved fresh phantoms into being. The smoke was not a veil anymore, but a stage. A stage where death itself performed an endless, graceful waltz.
Kagerou's tanto cut once more, sharp and final. The illusions collapsed into the mist, vanishing like fading dancers at the end of their act.
The boy stood at the center of the empty yard, breath calm, gray eyes gleaming cold in the moonlight. His tanto lowered, smoke still rising faintly from his skin.
Even with no enemy, the illusion had been absolute.
"…Not enough"
Kagerou's words drifted into the night air, swallowed by the lingering smoke. A bead of sweat traced his cheek, slid down his neck, vanishing into the collar of his yukata. He raised the kiseru to his lips, drew in the bitter taste of Indian tobacco, and exhaled slowly, the smoke curling like a vow.
"I should break my limit…" His grip on the tanto tightened. Muscles tensed, lungs expanded, his whole body braced to push beyond what it knew. The mist stirred as if answering him, coils of haze beginning to shift restlessly around his form.
But then-
*Waaahhh!*
A newborn cry cut through the silence.
Kagerou froze. His chest locked. For a single, fragile moment, it felt as though the world itself had paused. The fog stilled, even the air held its breath.
That sound… it pierced deeper than any blade.
His heart, clenched tight from endless training, shuddered, skipped a beat. The tanto in his hand lowered, trembling against his will.
"…"
The illusions dissolved, smoke unraveling into the night wind, leaving only the pale moonlight over the yard. Kagerou stood there, rooted, as if afraid the cry would vanish if he moved.
Another wail rang out. Raw, small, fragile. But alive.
"…So he's here," Kagerou whispered. His throat tightened, but his lips curved faintly, the barest shadow of a smile. "Little brother…"