A Legacy Reborn

The air within the Infinity Castle trembled as Kibutsuji Muzan stood in its ever-shifting corridors. The faint sound of Nakime's biwa echoed through the walls, each note bending the space around him. The walls twisted and folded with urgency, rearranging the labyrinthine halls in an instant, guiding Muzan to the heart of the castle. Shadows flickered across the wooden panels, recoiling as if afraid to draw too close.

Muzan's face, usually calm and unreadable, was tight with frustration. His crimson eyes gleamed with anger as the final corridor opened before him. The castle responded to his presence with nervous haste, its walls shifting aside without hesitation. A faint creak echoed through the air as the last panel slid away, revealing a vast, open chamber.

Lanterns hung from the distant ceiling, their dim light casting pale reflections across the polished floor. The room stretched into the shadows, its farthest edges swallowed in darkness. Muzan stepped forward, his cape trailing behind him as his presence seemed to weigh down the very air. His fingers curled into fists at his sides, nails biting into his palms. The faint scent of blood clung to the air, mingling with the distant hum of Nakime's biwa.

Silence fell as Muzan came to a halt at the chamber's center. His gaze was sharp, unwavering, and filled with an intensity that seemed to press against the walls themselves. The air grew heavy with unspoken tension, and the faint creaks of the castle's shifting walls slowed, as if holding its breath. Even the shadows seemed to hesitate, uncertain whether to approach or retreat.

The echoes of the castle settled into stillness, but the tension did not fade. The Infinity Castle, like its master, seemed to stand on the brink of something inevitable, waiting for the storm that had yet to break.

"Come forth, Kokushibo."

The air shifted with a low hum of biwa strings, and within moments, Upper Rank One emerged from the void. Clad in dark hakama and adorned with six haunting eyes, Kokushibo stood in front of Muzan, his aura cold and unwavering.

"Master," Kokushibo greeted, voice deep and steady.

Muzan's gaze bore into him, the unspoken gravity in his eyes tightening the air.

 "Yoriichi Tsugikuni has returned."

Silence fell like a blade between them. Kokushibo's breath caught in his throat, eyes widening in a rare display of shock. The weight of that name crashed through centuries of unspoken torment—a name that had carved an unhealed scar across both their lives. 

Muzan continued, voice sharpening with resolve, I will send the inferior demons to observe Yoriichi's movements from the shadows. They will not engage; their sole purpose is to gather information and report back. 

Stepping forward, Muzan's crimson eyes locked onto Kokushibo's.

"How is Yoriichi still alive?" His voice was low, laced with a rare trace of uncertainty. "He died long ago… by my hand." Said in confusion and fear by kokushibo.

Kokushibo's many eyes flickered with something unreadable—shock, confusion, or perhaps an ancient regret buried too deep to name. "I did. I witnessed his final breath with my own eyes."

Muzan's gaze darkened, thoughts twisting through possibilities both horrifying and impossible. His voice lowered to a whisper, yet it cut through the silence like the edge of a blade.

"Then the question remains... did Yoriichi achieve immortality—or has he found a way to traverse time itself?"

The air within the Infinity Castle seemed to hold its breath as those words settled into the marrow of its walls, echoing into the endless void beyond.

For the first time in centuries, Kokushibo found himself without words.

Muzan's voice pressed forward, each syllable cold with remembered terror. "I encountered him beneath the winter moon. He has returned from beyond time, unchanged. His strength... it remains as it was on the day he nearly destroyed me."

Kokushibo's hands curled into fists against his sides, though his face betrayed no emotion beyond the flicker of shock. Memories surged unbidden—blades clashing beneath crimson skies, the heat of Sun Breathing against flesh, and the unyielding gaze of a brother who had once stood beyond mortal reach.

"Summon the Upper Moons. The meeting is to be called off," Muzan commanded abruptly.

Muzan interrupted, voice low and edged with uncharacteristic urgency. "Their knowledge of Yoriichi's return would serve only to breed fear. Akaza, Doma... none must know. I will not have their resolve weakened."

Kokushibo uncertainty flickered behind his many eyes. "If Yoriichi has returned... what course of action shall we take?"

Muzan's silence was more chilling than any answer. The Demon King stood motionless, gaze lost within the depths of his own terror-laced thoughts. For centuries, he had ruled the night unchallenged. Yet the shadow of Yoriichi Tsugikuni—a mortal who had once brought him to the brink of annihilation—now loomed once more.

"We will observe," Muzan finally replied, his voice a cold whisper. Muzan's thought still fear coiled beneath the surface of his thoughts.

 "This time, we will not face him head-on. We No matter how radiant the sun may shine, it cannot burn what it cannot see."

Kokushibo remained silent, Muzan stood still, his pulse a steady rhythm beneath skin that remembered the burning edge of Yoriichi's blade.

And deep within the folds of darkness, fear whispered that this time, escape might not be enough.

The air within the Infinity Castle pulsed with the eerie resonance of Nakime's biwa, each solemn note weaving through the endless labyrinth of shifting walls and towering columns. The sound reverberated off polished stone and vanished into the shadows, as if the castle itself stirred in response to the melody. In the span of a heartbeat, the air thickened, heavy with a sense of anticipation as the space began to warp. Walls twisted and rearranged, shadows bending and folding in on themselves until they coalesced into solid forms. One by one, the Upper Moons emerged from the darkness—Akaza, Doma, Gyokko, Hantengu, and the sibling duo, Gyutaro and Daki. Their figures settled into the dim light, their crimson eyes gleaming with a mixture of curiosity and suspicion as they took their places in a loose semicircle.

A tense silence followed, broken only by the faint, fading echoes of Nakime's biwa. The air crackled with restrained power, each demon radiating an aura of malice that seemed to press against the walls themselves. Gyutaro shifted his weight, the bones protruding from his emaciated frame casting jagged shadows across the floor. His crooked nails dragged idly against the side of his neck, leaving faint scratches in their wake.

"Ah, how exciting! A surprise meeting with our dear lord," Doma chimed in with a playful grin, clapping his hands together. 

Then, his eyes flicked around the room, confusion crossing his features. "Wait... who died? We're all here. So why has Lord Muzan summoned us?"

"Tch. Stand back, fool," Akaza growled, his eyes narrowing as he shot a glare at Doma. "Don't make a scene."

"Why so serious, Akaza-dono? I'm just trying to lighten the mood." Doma chuckled, feigning innocence as his eyes glimmered with mischief.

"Enough," Kokushibo's voice cut through the growing chaos like a blade through fog. Rising to his full height, he surveyed the gathered demons with a cold, unyielding gaze. "Silence until Lord Muzan speaks."

The air grew still as all eyes turned toward Muzan. Crimson eyes gleaming with a mixture of authority and underlying tension, Muzan stepped forward. 

For a moment, no sound existed beyond the distant echoes of Nakime's biwa.

"Yoriichi Tsugikuni has returned," Muzan announced.

Shock rippled through the gathered demons. Akaza's fists clenched instinctively, Doma's grin faltered ever so slightly, and Gyokko's porcelain mask seemed to crack with unease. Gyutaro and Daki exchanged a glance, tension knotting their shoulders. Even Hantengu, trembling as always, seemed to cower further beneath the weight of the revelation.

Muzan's gaze swept over them, his voice heavy with the weight of ancient memory. 

This time Muzan continued, voice sharpening with resolve, "we will not face him head-on. Yoriichi's strength is unparalleled. The Demon Slayer Corps has allied with Yoriichi, and their strength has grown beyond what it was before. 

Stepping back, Muzan allowed the weight of his decree to settle over the assembly. No further instructions were needed; the path had been set. The Upper Moons bowed in unison, their expressions now hardened with purpose. The faint hum of Nakime's biwa.

The air hung heavy with unspoken tension as Muzan's decree settled over the gathered demons. None dared to move or speak, their gazes lowered in silent obedience. The faint hum of Nakime's biwa resonated softly within the ever-shifting walls of the Infinity Castle, a sound that signaled the end of the meeting. Yet, for a moment, the atmosphere remained thick with anticipation, as if the very air held its breath.

Kokushibo moved first. Without a sound, he stepped back, his six eyes glinting beneath the faint glow of lantern light. Unlike the others, he required no summons. Shadows seemed to gather around him, clinging to the edges of his silhouette as though drawn by an unseen force. In a blink, he vanished—his presence fading like a whisper carried off into the void. The faint rustle of his haori was the only trace left in his wake.

Nakime's pale fingers glided across the strings of her biwa, the note ringing clear and sharp through the vast chamber. The sound pulsed through the air like a heartbeat, and Doma was the next to depart. His smile flickered back into place, though the glint of unease in his golden eyes did not fade. With a flash of movement too quick to track, Doma vanished—spirited away to his quarters, where the echoes of laughter would soon mingle with the distant wails of his followers.

Another strum of the biwa reverberated through the air, this time deeper, more resonant. Akaza's shoulders squared as he stood tall, his gaze fixed forward. His fists clenched and unclenched at his sides as though eager for the battle ahead. The air around him wavered as Nakime plucked another note, and in an instant, he was gone—cast out into the mortal world where his hunt would begin anew beneath the endless night sky.

Gyokko stepped forward next, the faint rattle of porcelain echoing through the chamber as he adjusted his mask. His grotesque form shifted with anticipation, scales glinting faintly as his twisted limbs flexed. Nakime's fingers danced across the strings once more, and with a discordant hum, Gyokko vanished—carried off to the domain where his grotesque artistry would soon leave its mark.

Gyutaro and Daki stood side by side, their shared presence exuding a simmering tension that crackled beneath the surface. Daki's fingers curled and uncurled, her emerald eyes flickering with anticipation, while Gyutaro stood motionless beside her, his sunken eyes gleaming with silent menace. A rapid succession of notes filled the air, sharp and quick as daggers. The space around them warped as the walls folded inward, and with a final reverberation, they vanished—gone as swiftly as the others.

At last, only Hantengu remained. His trembling form seemed to shrink beneath Nakime's gaze, knees knocking together as fearful whimpers escaped his lips. The biwa's final note rang out—a long, drawn-out sound that reverberated through the air like a distant thunderclap. The space around Hantengu warped and twisted until he, too, was gone, leaving behind only the faint echo of his panicked breaths.

Silence descended once more. Only Muzan and Nakime remained within the vast, ever-shifting expanse of the Infinity Castle. The Demon King stood motionless, his presence suffocating even in stillness. His crimson eyes gleamed with a cold, unyielding resolve as he gazed into the void, where countless paths now stretched before him—the future woven from threads of blood and fear.

Without a word, Muzan stepped back into the shadows. Darkness swallowed him whole, and like a wisp of smoke, he vanished from sight.

Nakime lowered her biwa, fingers resting gently against the strings as the final echoes faded into stillness. The castle walls shifted and twisted once more, returning to their labyrinthine dance. Alone in the vast expanse, she tilted her head slightly, listening to the distant whispers carried through the void.

The meeting was over.