Nakime's Blood Demon Art activated, and Kokushibō was instantly transported to Kyōbetsu Island.
Kyōbetsu Island was small—lush and green, its forests dense with towering trees. Spring had come; blossoms of every kind filled the air with their fragrance, casting the island in an almost divine serenity.
Kokushibō advanced toward the island's center, where he discovered a vast complex of buildings.
There, standing before him, was a man—the very same Shrine Priest Yōsuke had encountered earlier.
The moment their eyes met, the priest spoke first, his voice calm, as if he had foreseen this meeting long ago.
"So, you've finally arrived, Michikatsu Tsugikuni."
Kokushibō's eyes narrowed.
"How do you know my name?"
The priest smiled faintly.
"I've been waiting for you for quite some time. Come with me."
Without another word, he turned and began walking toward the grandest mansion among the structures.
Kokushibō frowned, uncertain what this man's intentions were. Yet confident in his own overwhelming strength, he followed.
Inside the estate of the Shrine Priest clan, many figures dressed in the same ceremonial robes moved quietly through the halls. None seemed surprised or afraid at the sight of the horned, monstrous demon who had entered among them.
At last, they arrived within a chamber resembling a shrine. The priest stopped and spoke.
"You've come to exterminate the Shrine Priest clan, haven't you?"
Kokushibō's brow furrowed.
"Since you know that, why did you lead me straight into your stronghold?"
"We have already prepared ourselves," the priest said with eerie composure. "All of this is decreed by fate. The annihilation of our clan is already determined. However… the one who will destroy us is not you."
Kokushibō let out a low scoff.
"Pretentious fool! If you're all prepared to die, then why do you say it won't be by my hand?"
"Kibutsuji Muzan sent you here to capture us alive. Because of that, you are fated to fail."
A chill ran through Kokushibō's mind.
How could this man know that Muzan had ordered him to bring the priests back alive? That command had been given only moments ago—impossible for anyone else to know.
Rage surged within him.
"This place is far from the Infinity Castle," he hissed. "If I slaughter all of you here, no one will ever know."
He drew his demonic blade, the killing intent radiating from him like an inferno. But before he could strike, a crushing aura descended.
Behind him, four doors appeared at once—and from them emerged Kibutsuji Muzan himself, along with all remaining Upper Moons except Nakime.
Muzan's cold gaze fell upon him.
"So you've betrayed me once again, Kokushibō."
Kokushibō stiffened, his expression hardening.
"You knew?"
"Of course," Muzan replied icily. "Though I cannot read your memories, I can sense the hatred festering in your heart. I granted you immortality, allowed you endless years to hone your swordsmanship, and trusted you completely. I even gave you another chance. Yet in the end, you chose betrayal."
The curse within Kokushibō's body activated—an unbearable pain tore through him, driving him to his knees.
Muzan seized him by the hair and smashed his head into the ground. The earth cracked open beneath the blow, leaving a deep crater.
"You knew the curse within you would destroy you if you defied me," Muzan snarled, his face twisted with rage. "Tell me—why did you still choose to betray me?!"
Kokushibō couldn't respond; agony consumed him. It felt as though tens of thousands of insects were gnawing at his flesh from the inside out.
Muzan pressed his foot down on Kokushibō's back, crushing him further.
"Dōma, Hantengu, Kaigaku," he commanded. "Gather every member of the Shrine Priest clan and bring them to the Infinity Castle. Alive."
Kokushibō's vision blurred from pain and fury. But then, deep within his soul, a spark of will ignited.
The curse's torment began to wane.
He forced himself up—defying Muzan's control—and swung his blade with all his strength.
Muzan's eyes widened in surprise as he caught the demonic katana barehanded.
"Impossible… how could you undo my curse?!"
Kokushibō's voice roared with defiance.
"Kibutsuji Muzan! You no longer control me! I will stop you—even if it means dying together!"
"Moon Breathing, Tenth Form: Piercing Moon Thrust — Shattered Leaf, Waning Crescent!"
Twin arcs of whirling crescent blades erupted from his sword, spinning forward like twin full moons. Countless smaller moon blades followed, slicing through the air toward Muzan.
But Muzan unleashed a massive shockwave, scattering the attacks as though they were nothing.
"Futile," he said coldly. "Even if you've broken the curse, everything you are was given by me. I can reclaim it whenever I choose. Black Blood Thorn!"
He raised his right hand. A black thorn sprouted from his palm and shot forward at blinding speed.
Kokushibō slashed at it, but his blade couldn't cut through. The thorn impaled him squarely in the chest.
It spread within him like wildfire, sprouting through his flesh, piercing outward until his body was bound to the ground by jagged black spikes.
"This," Muzan said, his voice filled with contempt, "is the fate of those who defy me.
As punishment for your betrayal, you will wait here—until the sun rises—and burn to ash beneath its light."
Kokushibō struggled, but it was useless. Muzan was his creator; his power over Kokushibō's life and death was absolute.
As he watched Dōma, Hantengu, and Kaigaku rounding up the Shrine Priests, a deep, hollow despair welled inside him.
Then—
"Brother… have you given up already?"
The familiar voice of Yoriichi Tsugikuni echoed softly in his mind.
Kokushibō's head hung low.
"Yoriichi… I can't… I no longer have the strength."
"A samurai must never surrender. That was your teaching to me once—have you forgotten?"
"Yoriichi… I'm so tired."
"It is not yet time for us to meet again," Yoriichi's voice said gently. "This is not the end.
Tell me, brother—do you still remember the Breath of the Sun?"
"You know I could never master it."
"We share the same blood. And now, you have finally reached the point where you can use it."
But even as those words reached him, Kokushibō felt no joy.
The technique he had longed for his entire life—the one that had driven him into despair—was now within reach, but he had long since ceased to be human.
"Yoriichi… I am a demon now. Even if I could use the Breath of the Sun, its flames would burn me to ash."
"Then let me lend you my strength—one last time, brother."
Kokushibō felt a hand—warm and light—rest upon his own, guiding the hilt of his blade. Flames erupted from the sword, golden and pure, and then engulfed his entire body.
The thorns binding him were consumed instantly. The flames scorched his flesh, yet an extraordinary power within him began to heal his body as fast as it burned.
Bathed in divine fire and moonlight, Kokushibō stood once more.
Within the flames, strength surged through him—ancient, sorrowful, and unyielding.
"Yoriichi…" he murmured, voice trembling. "Even after all this time… it's still you who protects me."