The sun sank beneath the horizon, staining the sky in deep hues of crimson and violet. Its fading light cast long, jagged shadows over the dense, oppressive forest of Mount Natagumo, where gnarled trees loomed like silent sentinels. The dirt path beneath Yoriichi and Giyu's feet felt colder with every step, as if the mountain itself was warning them of the horrors that lay ahead. The air was heavy, thick with something unseen—an overwhelming malice that clung to their skin like an invisible shroud.
Giyu's fingers tightened slightly around the hilt of his blade. Though his face remained impassive, his sharp senses told him what his instincts already knew—this place was infested. The stench of demons, acrid and suffocating, lingered in every breath he took. He had fought in many battles, faced countless enemies, but there was something different about this mountain. Something unnatural.
His gaze flickered toward the man walking beside him. Yoriichi moved without hesitation, his steps measured and deliberate, as if the ominous presence surrounding them was nothing more than a passing breeze. There was no tension in his shoulders, no sign of unease—only the quiet, unwavering composure of someone who had long transcended fear.
Giyu had seen strength before, had fought alongside the mightiest swordsmen of their era, but Yoriichi was different. He was an enigma—his presence serene yet commanding.
But there was no time to dwell on such thoughts. The silence around them had shifted, thickening into something far more sinister. The darkness between the trees stirred, and from its depths, glowing eyes flickered to life.
Does he not feel this? Giyu thought. This overwhelming hostility in the air?
As they neared the outskirts of an old, abandoned household, the oppressive atmosphere grew heavier, suffocating in its intensity. The air itself felt wrong, thick with a malicious presence that clawed at their senses. Before them stood a treehouse, its wooden beams warped and rotting from years of decay. The structure swayed slightly in the evening breeze, its creaking unnervingly loud against the eerie silence of the forest. But the true horror wasn't the state of the house—it was what lurked within it.
From the gnarled branches above, faint glimmers of red flickered in the darkness. Multiple sets of glowing eyes peered down from the treetops, watching, waiting. The branches trembled, not from the wind, but from the shifting of bodies—small, grotesque figures crawling along the bark like oversized insects. A sickly chittering sound filled the air, growing louder, more frenzied, until it was a deafening chorus of hunger and malice.
And then, they came.
From the treehouse and the canopy above, dozens of spider-like demons lunged forth. Their small, contorted bodies twitched unnaturally, thin limbs splaying out like the legs of a true arachnid. Despite their size, their movements were disturbingly fast, their gleaming claws slicing through the air as they swarmed toward Yoriichi and Giyu in a writhing mass of pale flesh and clicking mandibles.
Giyu inhaled sharply, stepping forward. His grip on his katana tightened.
"Water Breathing, Fourth Form: Striking Tide!"
With a single, fluid motion, his blade sliced through the incoming demons. His movements were swift, his slashes relentless, like a never-ending tide crashing against the shore. The demons shrieked, their bodies severed in an instant before they dissolved into nothingness.
Yoriichi watched quietly, his face unreadable.
Giyu exhaled, adjusting his stance. He had cleared a path, but more demons were coming. Yet, before he could raise his blade again, something strange happened.
The remaining demons—stronger, larger—ignored him. Instead, they turned their attention to Yoriichi, their bodies trembling, not in hunger, but in something far worse. Fear.
And then they attacked.
But Yoriichi… he remained still.
Not until he exhaled.
"Third Form: Raging Sun."
A single step forward. A breath drawn. Then, the night itself seemed to fracture.
Golden arcs of light tore through the air, twin slashes so swift and precise they left trails of brilliance lingering in the darkness. The battlefield was momentarily bathed in a fleeting glow, shadows twisting and stretching as if recoiling from his presence. The force of his strike sent a sharp gust rippling outward, rustling the trees, stirring the dust, and forcing even the stars above to bear silent witness to the moment.
Then stillness.
In the span of a single heartbeat, it was over.
The demons did not scream. They did not struggle. Their bodies, once filled with malice and hunger, stood frozen, as if their very existence hesitated to acknowledge what had transpired. Limbs severed, torsos cleaved apart—the precision of his blade so absolute that for an instant, they remained whole, unaware that death had already embraced them.
A breeze passed through. And with it, their bodies fell apart.
No resistance, no remnants, no sign that they had ever been there at all. Their very essence was erased, reduced to drifting embers swallowed by the endless night. The silence that followed was deafening, the weight of the moment pressing upon the world itself.
Giyu's breath caught in his throat. His fingers, once tense around his katana's hilt, loosened unconsciously. A cold chill ran down his spine—not from fear, but from something far more profound.
What… was that?
He had fought alongside countless Demon Slayers, had witnessed the strength of warriors who stood at the pinnacle of their era. He had seen the ferocity of the Hashira, had stood beside legends, had even felt the overwhelming power of those stronger than himself. And yet—this… this was different.
This was not mere skill. It was not refined technique, nor the product of training honed over years. No, what had just unfolded before him was something beyond human limits, something that defied everything he understood about battle.
It was as if the world itself had bowed in submission, as if the very concept of struggle had been rendered meaningless in the presence of that blade.
The silence that followed was suffocating.
The wind had stilled. The forest, once alive with the rustling of leaves and distant calls of nocturnal creatures, had gone utterly quiet, as if nature itself dared not intrude upon what had just transpired. Even the remnants of the demons—had there been any to leave behind—had vanished without a trace, as though they had never existed at all.
And then, movement.
A shift in the air. A presence calm, unshaken.
A blur of fluttering fabric descended from the trees, graceful and precise. Before either of them could react, the figure struck, driving the tip of a blade into the neck of a lurking demon.
There was no resistance.
No time for the demon to react.
Its body convulsed before it swelled unnaturally—then exploded.
Giyu barely flinched as the girl landed lightly before them, adjusting the sleeves of her butterfly-patterned haori. Her violet eyes twinkled with something akin to amusement as she glanced at him.
"Ah, Tomioka-san. Fancy meeting you here."
"Kocho," Giyu acknowledged with a nod.
Her gaze flickered to Yoriichi, and her expression shifted—curiosity, confusion, a fleeting moment of something unreadable.
"And you are?"
Yoriichi met her gaze, his voice calm as he answered, "Yoriichi Tsugikuni."
Shinobu blinked. A polite smile tugged at her lips. "I see. I am Shinobu Kocho, the Insect Hashira."
There was something peculiar about him something just beyond her grasp. The air felt heavier in his presence, not in an oppressive way, but as if it carried the weight of something long forgotten. His demeanor was calm, his words measured, yet there was an undeniable depth to him, like the still surface of a lake hiding unfathomable depths. Shinobu, ever perceptive, caught onto it immediately.
Still, she chose not to pry. Perhaps it was intuition, or perhaps it was the quiet understanding that some things were better left unspoken. With a polite, almost knowing smile, she offered a brief farewell before turning away. Her duty called her elsewhere to recover the injured Demon Slayers deeper in the mountain. Yet, even as she walked away, she couldn't shake the lingering feeling that she had just crossed paths with something, or someone, far beyond her understanding.
As for Giyu and Yoriichi, their journey was far from over.
The deeper they ventured, the thicker the presence of demons became. Yoriichi's mark burned faintly against his skin a silent warning.
Something was ahead.
Something… strong.
A house loomed in the distance, its silhouette barely visible through the thick fog. And standing before it was a demon unlike the rest.
Its presence was suffocating.
The creature smirked, eyes glowing with malice. Then, with a flick of its wrist, razor-sharp threads shot forward, cutting through the air like blades.
Yoriichi's hand tightened around his katana.
And then he dodged !
From the swirling mist, a figure emerged.
Small, almost fragile in appearance, the demon stood at the center of the path, illuminated by the pale glow of the moon. A boy—at least, that's what he seemed to be at first glance. His face was delicate, porcelain-like, marred only by a thin red pattern that stretched across his skin like cracks in fine china. His snow-white hair cascaded over his shoulders, framing wide, crimson eyes that glowed with eerie intensity.
Despite his childlike form, his presence was suffocating.
Yoriichi could feel it—the sheer weight of his existence pressing down on the world itself. It was unlike any ordinary demon. This one carried something else, something far more sinister. A name etched into its very being.