Kibutsuji Muzan was pinned to the ground by the Priest Master, unable to move.
Yōsuke hurled the Ame-no-Murakumo Sword like a spear straight toward Muzan.
"Blood Breathing, Fifth Form — Blood Flash!"
Before the divine blade could pierce Kibutsuji Muzan, Yōsuke arrived at the tip a split second earlier.
The Ame-no-Murakumo Sword ran through both Yōsuke's and Muzan's bodies.
Yōsuke wrapped his arms tightly around Muzan, refusing to let him escape.
Muzan thrashed violently, trying to split and flee, but the flames of Sun Breathing burning on Yōsuke's body kept suppressing him.
The Priest Master watched coldly from the side.
Even though both Muzan and Yōsuke were impaled by the divine sword, he did not lift the gravity binding on everyone, wary that Yōsuke might attempt something, ready to prevent any sudden change.
Furious beyond reason, Muzan roared at Yōsuke:
"Let go of me! You bastard!"
"Let go…? From the moment you and I were born, we've been tangled together. What's there to let go of, my brother?"
Feeling the flames scorch his body, Muzan's rage only grew.
"Why? Why do you keep standing in my way?!"
Yōsuke whispered softly,
"Because I want to break free from destiny… and gain freedom."
Desperate to survive, Muzan hurriedly offered a deal:
"If you die, you'll lose everything! We can join forces—kill that Priest Master together! Then I swear, I will never kill another human again. From now on, demons and humans will never interfere with each other!"
"You think I'd believe that? Kibutsuji Muzan… you're far too greedy. Even if you choose to stop now, someday your desires will take control of you again. Don't worry—I'll stay with you. You won't be alone."
Yōsuke looked toward the comrades still pinned down by gravity. Their faces were already streaked with tears, full of unwillingness and grief.
With a warm smile, he spoke gently,
"Don't cry for me. I'll become the free wind, drifting across every corner of the earth. When a gentle breeze brushes your cheek… that's me coming to visit you."
As he looked toward the approaching sunlight that was about to pour across the land, a faint regret surfaced in Yōsuke's eyes.
"At the very end… may I feel the warmth of the sun one last time…?"
As if the sun heard his wish, its light shone upon Yōsuke's body.
The moment the light touched them, the flesh of both Muzan and Yōsuke began to sizzle and rot away at frightening speed.
But Yōsuke didn't mind—in fact, he seemed to savor it.
"Thank you… it's truly warm…"
Muzan was overwhelmed with terror.
"Get away! Get away from me!"
"Kibutsuji Muzan… our era ended a thousand years ago. We're relics of an old age. It's time we step aside and let future generations welcome a new dawn."
Facing imminent death, Muzan suddenly stopped struggling and, strangely, burst into laughter.
"Hahaha…"
His laugh was desolate, yet held no fear of death.
"My thousand years of effort—gone in an instant. Until now, everything I intensely desired, I always achieved. Yet… what one individual can accomplish is limited after all. I must admit… what humans often say is true: 'a person's will is eternal.'
All living beings die. Only will is everlasting.
It's true. I remember none of the people I killed—the death of the body is the true end.
But will… it's inherited, never destroyed. Even I was defeated by that very will. I witnessed it with my own eyes… and now I tremble from being moved."
Yōsuke could sense that Muzan's thoughts were genuine.
Looking at the companions desperately calling Yōsuke's name, Muzan suddenly felt a deep loneliness.
"But… I regret it now. It's far too late for me to understand. If only I had nurtured a successor—someone to inherit my will—maybe things would look very different now.
I envy you, Yōsuke. Even though you perish, your will remains eternal, undying. In the truest sense… you are immortal."
"Weren't your subordinates your successors? But you never truly acknowledged them. You only treated them as tools to realize your goals."
Muzan recalled the familiar faces of the Twelve Kizuki and let out a bitter smile.
"So I was the one pushing them away all along… how ironic."
Under the sunlight, the bodies of both Muzan and Yōsuke slowly turned to ash.
In Muzan's eyes, there was no anger, no hatred—only peaceful acceptance.
"Yōsuke… this time, I've lost completely. You've won…"
Yōsuke smiled.
"Is that so…? I finally won. My promise… is finally fulfilled. Don't worry, even in death… you won't be alone."
"Hmph… After a thousand years, even in death you keep clinging to me. Aren't you tired? …Fine. With you here, I suppose I won't be lonely. I'll go on ahead."
Muzan opened his arms as if welcoming liberation, letting the sunlight wash over him as he completely dissolved into ash.
Half of Yōsuke's body also turned to dust, and he collapsed weakly to the ground.
Seeing everything come to an end, the Priest Master finally released the gravity binding.
The Butterfly Sisters immediately rushed to Yōsuke, gently helping him up.
Hakuji, Gyutaro, Koyuki, and Ume used a huge wooden plank to shield him from the sun.
"Master—no, you're not going to die… There has to be a way! There must be!"
Kanao took out a vial of the human-conversion drug and injected it into Yōsuke.
If he could become human again, the sun would no longer harm him.
But the drug needed time to take effect—and for someone at the level of the Demon King, the conditions were far more difficult.
"Why won't it stop? Please… stop! Stop disappearing!"
Kanao and Shinobu injected every medicine they had into Yōsuke, but nothing slowed the disintegration.
Hakuji, Gyutaro, Koyuki, and Ume were also overwhelmed with grief.
Yōsuke could barely feel his body anymore. Forcing a smile, he said:
"Don't cry. Shouldn't you be happy for me? To have met all of you… that was truly wonderful…"
Using the last of his strength, Yōsuke raised his arm to wipe away the sisters' tears.
But halfway up, his arm turned to ash.
Despite the clear sunny sky, it suddenly began to rain.
Raindrops slid down everyone's cheeks, unable to hide their sorrow.
With his final breath, Yōsuke gave his last message:
"Please… live on happily…"
And then Yōsuke completely turned to ash, disappearing into the sky.