The central palace of the Infinity Castle was still shrouded in thick black mist.
Ink-like liquid flowed across the floor, each drop radiating suffocating demonic energy.
Mushiki knelt on one knee at the center of the hall. His black kimono was still stained with battlefield blood, and his dark red, slit pupils showed no emotion—only absolute obedience to Muzan.
"You've done well, Mushiki."
Muzan hovered in the air, his jet-black hair drifting through the mist, crimson eyes gleaming with pleasure.
"Watching those Hashira and that group of brats struggle in your memories truly brightened my mood."
He extended a hand. Black mist coalesced into a thin thread, which slowly entered Mushiki's body—blood even thicker and more potent than before.
Mushiki could feel it coursing through him, his demonic power swelling rapidly. Even the regeneration of his severed limbs had become slightly faster.
He bowed his head slightly and said calmly, "It is my duty to serve you, Muzan-sama."
"Good."
Muzan nodded with satisfaction and waved his hand dismissively.
"Go. Absorb that power well. Next time you face the Hashira, do not let them escape again."
"Understood."
Mushiki rose and turned toward the hall's exit. Behind him, the black mist slowly thinned as Muzan's pleased laughter echoed through the vast chamber like the hiss of a serpent.
Leaving the central palace, Mushiki didn't return to his quarters. Instead, he walked toward the deeper section of the Infinity Castle.
There, hidden in a quiet corner, was a dojo—Kokushibo's personal training and resting place.
He wasn't sure why his steps led him there, only that something inside urged him—perhaps a faint instinct whispering that he might find answers in Kokushibo's presence.
Answers about the strange unrest within him.
The dojo door was open. From inside came the crisp, rhythmic sound of go stones striking a wooden board.
Mushiki stepped in. At the center of the dojo sat an old go table, its surface marked by years of use.
Tsugikuni Michikatsu—Upper Moon One, Kokushibo—sat before it in his purple-black haori, silently playing against himself.
His six eyes were fixed intently on the board. Each black stone he placed landed with a soft tock, echoing clearly in the still air.
The board was already dense with stones—black and white intertwined in a complex, unending struggle.
Kokushibo seemed unaware of Mushiki's presence. He continued playing alone, fingers holding the next stone in thought before setting it precisely in place.
Mushiki said nothing. He walked quietly to the opposite side of the board and stood still, his gaze falling over the tangled sea of black and white stones.
He didn't understand the game. All he saw was chaos.
The dojo was silent except for the sound of the stones being placed and their calm, steady breathing.
The black lanterns hanging overhead swayed slightly, casting broken shadows that rippled across the tatami.
After about fifteen minutes, Kokushibo placed his final black stone, trapping a large cluster of white stones completely.
He finally lifted his head. All six eyes turned toward Mushiki. His tone was flat.
"You came to see me?"
"Yes."
Mushiki answered, his gaze still on the board.
"Kokushibo-sama, you were playing alone?"
"War and the game of go are alike," Kokushibo replied, turning a white stone between his fingers. "Playing against oneself clarifies each gain and loss."
He then looked up, expression unchanged. "Would you like to play a match?"
Mushiki froze for a moment before shaking his head. "I'm not skilled in such things. I would only disturb your focus."
"It's fine."
Kokushibo pushed a white stone toward him. "In every art, talent counts for nine parts, learning for one.
Some are born to master something at a single touch; others labor decades and still fall short of a child's grasp. Try it. Perhaps in this, you'll find a gift of your own."
Mushiki hesitated, staring into Kokushibo's unblinking eyes. Then, quietly, he sat down.
He picked up a white stone, hesitated for a long while, and finally placed it clumsily near the board's edge—neither threatening the black stones nor defending his own.
Kokushibo's six eyes flickered, showing a rare hint of exasperation. Still, he set a black stone on a critical point that revived half the board.
"When playing, consider the whole field," he said evenly. "Don't place stones at random."
Mushiki nodded and picked up another white stone, placing it clumsily inside the cluster of black stones. It was immediately surrounded—already a dead piece.
Kokushibo's hand paused for a brief moment before he sighed lightly. "That move... is a gift to your opponent."
For the next half hour, the dojo echoed with the sound of Kokushibo's calm instructions and Mushiki's awkward placements.
Every move Mushiki made seemed chaotic—either handing over stones for free or blocking his own path, turning what could have been a fine game into a complete disaster.
At last, Kokushibo looked at the board, now nearly cleared of white stones, and set his piece down with a faint, helpless tone. "It seems... this isn't your talent."
Mushiki didn't argue. He silently gathered the white stones, his face expressionless. He had never cared for the game anyway—he had only wanted an excuse to stay and ask what was truly on his mind.
After a pause, he finally spoke. "Kokushibo-sama... do you still remember your human memories?"
Kokushibo's body stiffened. His six eyes flickered with a faint, complicated emotion—something that broke through his usual calm.
He was silent for a long time before answering slowly, "Most of them... are gone."
"Gone?" Mushiki asked.
Kokushibo's gaze drifted, as though peering through centuries of haze. "I remember having a wife... and children. But their faces, their voices—I can't recall them. Only blurred fragments remain."
His fingers traced along the wooden edge of the board. His voice softened, carrying a rare hint of melancholy even he seemed unaware of.
"Those memories are like fog—the more I try to see them, the more they fade. Only one person remains clear in my mind."
"Who?" Mushiki pressed.
"Tsugikuni Yoriichi."
Kokushibo's tone dropped low. In the depths of his six eyes flickered a storm of emotions—resentment, fury, and something wordless that almost resembled reverence.
"His face, his swordsmanship, his presence—they're all still vivid in my memory. I remember the first time he picked up a blade... I remember him cutting down a demon with Sun Breathing... and I remember our final battle."
He shook his head slightly, as though to cast off the ghosts of memory, his voice regaining its cold detachment.
"But none of that matters now. For one who seeks eternal strength as a demon, human memories are only burdens. To move forward—to reach a higher realm—you must let go of the past."
Mushiki fell silent. Kokushibo's words didn't ease his confusion—they only deepened it.
He recalled the battlefield—the sight of Tō covered in blood, his arm severed; the searing pain in his own chest at that moment.
He remembered Kamado Tanjiro's desperate cry of "Giyu-san!"—and the flash of images that had erupted in his mind.
He remembered the sorrow and fear in Kocho Kanae's eyes when she faced him.
"Why..."
Mushiki murmured softly, pressing a hand against his chest. There was no heartbeat—yet he could still feel something stir there.
"Why does my body react when I see those fragile humans? They called me 'Giyu'… that name… it feels so familiar. Was that my name when I was human?"
Kokushibo looked at him, studying him intently with all six eyes. "You're troubled by this?"
"I don't know."
Mushiki shook his head, for the first time showing uncertainty in his gaze. "It feels like those memories mean something. Like I've lost something… important."
"There's no need to dwell on it."
Kokushibo rose and walked to the window, staring into the endless darkness beyond.
"Muzan-sama gave you a new name and a new existence. You only need to fulfill your role as Upper Moon Two. Human memories will only cloud your will and weaken your pursuit of power."
Mushiki said nothing, only watching Kokushibo's back in silence.
He knew the words were true. As Muzan's weapon, he shouldn't feel these things—shouldn't question his purpose.
But the echoes in his body, the fragments in his mind, wrapped around him like vines—tightening, refusing to fade.
"You once asked me," Kokushibo said suddenly, turning his head slightly, "if Moon Breathing still has room to evolve."
Mushiki blinked, caught off guard.
"Your swordsmanship already encompasses all known forms of Moon Breathing," Kokushibo continued evenly, "but what you lack is intent—the true will behind the blade. Starting tomorrow, I'll train with you personally, to refine that intent."
Mushiki hesitated for a second before bowing his head. "Thank you, Kokushibo-sama."
"Go, then."
Kokushibo waved a hand and sat back down before the go board. He picked up a single black stone but didn't place it—only stared quietly at the board, lost again in the shadows of memory.
Mushiki rose and walked out. The dojo doors slid shut behind him, sealing away the silence within.
As he moved through the endless corridors of the Infinity Castle, black mist coiled at his feet. Images flickered through his mind—Tō's tears, Tanjiro's screams, Kanae's trembling voice, and the determined eyes of the Flame Hashira as his life faded away.
"Giyu..."
He whispered the name again, a faint ache spreading through his chest.
He didn't know what truth hid behind it—what bond connected him to those humans.
He only knew that this confusion, this pulse deep within him, might one day become a chain he could never break.
When he returned to his room, Mushiki sat by the window, gazing into the eternal blackness beyond.
He raised his hand. Faint blue ripples of water formed at his fingertips, then slowly faded away.
Kokushibo's words echoed faintly in his ears.
Outside, the black mist churned endlessly, the Infinity Castle drowning in perpetual night.
Yet deep within Mushiki's heart, a tiny glimmer of light began to flicker—
a light born of lost memory, of self-questioning, and perhaps... the faintest spark of hope that one day might change everything.