Ten thousand years had passed since the fall of the first generation of heroes. Their names were long forgotten, buried under layers of myths, echoes in the ruins of once-proud temples and shattered swords resting beneath demon-carved monuments.
In that time, Shinsui, the Demon God King, had shaped the world to move in cycles—cycles of light and shadow, hope and despair. Every five hundred years, without fail, a Demon King would rise from the Abyss.
It wasn't random.
Shinsui had carved the pattern into the bones of the world itself—a law of his own making. Each Demon King bore a piece of the Abyss, infused with cursed essence and infinite potential. But no matter how strong, no matter how cruel, they would always fall. Always.
Because the world would answer.
A hero would rise. Born with divine blessing. Drawn by fate. Honed by suffering. Loved by the people.
And the Demon King would fall.
Again.
And again.
And again.
It was a story both Heaven and Abyss needed—Heaven, to create gods from souls of fallen heroes. The Abyss, to keep hatred and fear boiling at the edges of existence. And Shinsui? He watched it all like a bored playwright reviewing his final script.
There was nothing more for him here.
He had created everything he could. Gods, monsters, civilizations, paradoxes. The Abyss thrived under the rule of Satan—a Demon God created from spite, fury, and absolute loyalty. Gaia ruled Heaven, sculpting divinity from the hopes of mortals. She had become what she was always meant to be: the counterbalance to him.
The two of them now stood at the edge of existence, staring out into the swirling void between worlds. It was silent, but not uncomfortable.
"You've decided to go," Gaia said.
Shinsui didn't answer right away. His eyes glowed with ancient knowledge, and behind his gaze were worlds upon worlds he'd walked, ruled, and reshaped.
"I have," he finally said. "This world... it's finished. The loop will keep turning. I've made sure of that."
Gaia looked at him without emotion, yet somehow, it felt like disappointment.
"You've become something beyond this place. Beyond creation."
"Yeah," Shinsui said with a chuckle. "Funny, isn't it? I started off just trying to stretch my legs. Now I'm a cosmic law."
"You could stay. You've earned that right," she said. There was no desperation in her voice—only a strange sort of reverence. Like she understood that gods and devils alike could still drift apart.
"You know I can't," Shinsui replied. "I've already stayed too long. My world... the one I left behind... it still calls to me. I need to see it again."
Gaia raised a hand. Creation energy pulsed through her palm. She pressed it lightly to his chest, just over his heart. The gesture meant nothing. And yet, it meant everything.
"My blessing," she said simply. "Take it with you."
"No need for drama?" he joked.
"There never was," she answered.
And just like that, Shinsui turned, stepping into the portal of his own making. The laws of this world bent and cracked around him as he crossed the dimensional boundary.
He was leaving behind gods, monsters, empires, legends.
But he wasn't looking back.
—
He emerged in a cave.
The same one.
The same rock. The same stale air. The same soft crackle of a torch burning low. His clothes were different now—woven from void energy and stitched with divine threads—but the world around him had not changed.
To the Uzumaki who had released him, not even a second had passed.
The young man's eyes widened. "What... what just happened?"
Shinsui stretched his neck and rolled his shoulders. "You wouldn't believe me if I told you."
"You just stepped in and out of the portal!"
"To you, maybe." Shinsui glanced at his hands, now still and calm, yet hiding enough power to level entire realms. "But to me... it's been ten thousand years."
The Uzumaki's mouth hung open. "What?"
Shinsui sighed. "Long story. Not worth your lifespan."
He stepped past the stunned boy, eyes already scanning the forested horizon outside the cave. The world hadn't changed. Not one second had ticked forward. But he had.
He was no longer the sister of Mito. No longer a relic of the Warring States.
He was the Demon God King. The one who had seen all, gained all, and returned not as a wanderer—but as a sovereign.