The eerie sound of the biwa reverberated through the endless void of the Infinity Castle, its haunting melody twisting through the labyrinthine corridors like a serpent slithering through the dark. The air itself seemed to tremble with each note, the very fabric of the castle bending to the will of its unseen player.
One by one, the Lower Moons materialized in the vast, shifting chamber, their forms flickering into existence as if pulled from the depths of some nightmarish dream. Their eyes darted wildly, struggling to comprehend the impossible geometry of the space—walls that stretched into infinity, ceilings that dissolved into abyssal darkness, staircases that spiraled into nothingness.
A heavy silence settled over them, broken only by the distant, rhythmic plucking of the biwa's strings.
Then—she appeared.
Tall, elegant, her presence alone enough to make the air thicken with dread. Long, silken hair cascaded down her back, framing a face so flawless it seemed carved from marble. Her crimson eyes glowed with an otherworldly light, piercing through the shadows as she regarded the gathered demons with an unreadable expression.
The Lower Moons stiffened, their instincts screaming at them to kneel, to grovel, to beg for mercy before this terrifying figure.
"Who… who is she? one of them whispered, voice trembling.
The woman's lips curled into a slow, knowing smirk.
"You don't recognize me?" Her voice was smooth, melodic, yet beneath it lay something far more sinister—a predator's amusement.
And then—it struck them.
The scent. The aura. The sheer, suffocating weight of his power.
This was no woman.
This was him.
Muzan Kibutsuji.
The moment the realization dawned, the demons dropped to their knees, foreheads pressing against the cold, shifting floor. Their bodies shook violently, sweat beading on their skin despite the chill of the castle. None dared to lift their gaze, none dared to breathe too loudly.
Muzan observed them with detached indifference, his crimson eyes flickering over their cowering forms.
"Rui was killed."
The words were spoken softly, yet they carried the weight of an executioner's axe. The silence that followed was deafening.
"The Upper Moons have remained unchanged for centuries," Muzan continued, his voice devoid of emotion. "But you… the Lower Moons… you are always changing. How many times must I replace you?"
A ripple of terror passed through them.
"I am dismantling the Lower Moons."
The declaration sent a shockwave through the chamber. The demons' minds reeled, panic clawing at their throats—but none dared to speak.
None except one.
The Sixth Lower Moon, his fists clenched so tightly his nails drew blood, gritted his teeth.
'Its Easy for you to say… but for us—'
Muzan's gaze snapped toward him.
"Easy for me to say?"
The demon's breath hitched.
A heartbeat later—his body twisted violently, bones snapping like dry twigs, flesh rending apart as if torn by invisible claws. Blood erupted from him in a grotesque fountain, splattering across the floor in a thick, glistening pool. His remains collapsed in a wet heap, limbs bent at unnatural angles, his face forever frozen in horror.
The other demons flinched but remained motionless, their terror absolute.
Muzan flicked the blood from his fingers, his expression cold. "Pathetic."
The word hung in the air like a death sentence.
Then—movement.
One of the Lower Moons, driven by sheer, mindless terror, turned and bolted. His legs pumped desperately, his mind screaming only one thought to run and survive, he tried to escape but,
Muzan didn't even turn.
A blur—a flicker of movement—and then the demon's head was no longer attached to his body.
Muzan held it aloft, his fingers tangled in the demon's hair. The decapitated head's eyes were wide, lips still parted in a silent scream.
The body crumpled to the ground.
Slowly, Muzan turned his gaze to the remaining demons. His eyes locked onto Enmu, the last of the Lower Moons who had yet to be addressed.
With a flick of his wrist, he tossed the severed head at Enmu's feet. It rolled to a stop, blood smearing across the floor.
The final Lower Moon—a trembling, desperate wreck—dropped to his knees, forehead slamming against the ground.
"P-please, Lord Muzan! Give me a chance! I will prove my worth!"
Muzan tilted his head slightly, as if considering the plea. Then—
"With this useless power and pitiful strength?" His voice was soft, almost mocking. "You think I would let you live?"
The demon opened his mouth to beg again
And then he was gonna,
Dead
His body disintegrated in an instant, flesh and bone dissolving into nothingness, as if he had never existed at all.
Only Enmu remained.
Muzan stepped toward him, his presence suffocating.
"You are the last. The strongest among these failures."
Enmu did not speak. He did not dare.
Muzan raised a hand.
A surge of power—raw, overwhelming—flooded Enmu's veins as Muzan's blood forced its way into him. His body convulsed, muscles tearing and reforming, bones cracking and mending stronger than before. The pain was excruciating, a fire that burned through every nerve—but beneath it was something else.
Power.
True, undiluted power.
Muzan leaned in, his voice a whisper that slithered into Enmu's mind like a serpent.
"Kill all passengers aboard the Mugen Train. Leave no survivors."
Enmu gasped, his body still trembling from the transformation. His lips curled into a slow, manic grin.
"Yes, Lord Muzan."
Muzan turned away, already dismissing him.
"See that you don't."
The Infinity Castle shifted, the walls warping, the floor dissolving beneath Enmu's feet—and then he was gone, swallowed by the abyss, sent forth to carry out his master's will.
Silence returned to the chamber.
The scent of blood hung heavy in the air.
Muzan stood alone amidst the carnage, his crimson eyes gleaming in the darkness.
Somewhere, unseen, the biwa's strings twanged once more—a final, dissonant note.