Chapter 1 — The Furnace of Worlds
The air in the Gu world tasted stale. Not like dust or smoke — worse. Like eternity itself had been chewed up, swallowed, and spat back out.
Gu Yue Fang Yuan walked across the empty mountains, his boots barely making a sound on cracked stone. Nothing stirred. No wind, no birds, no insects. Only silence, heavy and thick enough to choke. He could have stomped and screamed, and the mountains would have swallowed the sound and forgotten it.
Eternity. Boring.
He tilted his head and watched the sunless sky, a web of colorless clouds swirling in slow, deliberate circles. For a few moments, he wondered: had he already seen everything?
Probably.
Probably everything worth seeing.
Fang Yuan's lips curled—not a smile. Just an acknowledgment. There was no challenge left in this world. No threat. Nothing that could touch him. Nothing that could make him pause, think, or hesitate. And yet… something prickled at the edge of his awareness. A crack. A fracture in the rules he had conquered.
He stopped. Fingers flexed, claws of thought digging into the silence. The air trembled, subtle, almost imperceptible. A presence arrived, not walking, not flying. It simply was. Like gravity shifting in reverse.
"You are Gu Yue Fang Yuan," the presence said. Not with voice, but with inevitability. A command without sound.
"Good," Fang Yuan said. "I've been bored anyway. Tell me why you've bothered me."
No flinch. No apology. Just… power.
"I offer you a choice," it said. "You are eternal. You have mastered all that you can master. You have devoured chaos. You have laughed at Heaven itself. But there is… stagnation. You will remain, but the worlds themselves are finite. You will grow no further. I offer… evolution."
Fang Yuan narrowed his eyes. Evolution. He had seen this word in cultivators' mouths for centuries. And yet he had no patience for it. Most evolution was a trap, a half-baked promise leading to death.
He tilted his head. "And you are…?"
"An instrument. A god, perhaps. Or something similar. Your concern is irrelevant. I am here to offer the Core."
Fang Yuan raised a brow. Core? That word alone could mean nothing… or everything.
The Core appeared as a black sphere, writhing, humming like a heartbeat trapped in stone. It was not alive. Not dead. But the moment Fang Yuan touched it, he knew. It could bend worlds. It could adapt, grow, evolve. Mahoraga's principle, but magnified. Perfect adaptation. A key to all worlds.
He touched it. Nothing happened. But it hummed inside his mind, whispering calculations, probabilities, weaknesses of places he had never been.
"Price?" Fang Yuan asked. Short. Brutal. Interested only in efficiency.
"You will face risk. Mortality. Fail, and you die permanently. The Core will not save you. You will be sent to other worlds. One at a time. Each a crucible. Each designed to temper you."
Fang Yuan tilted his head, lips twitching. Finally, he thought. Something that might be worth his time.
"I accept," he said.
The world trembled. Mountains cracked. Valleys split. The Core's light swallowed everything around him. And then… another presence arrived.
A weak, trembling human. A soul from Earth. Confused. Afraid. Perfect for mapping the worlds he would walk.
Fang Yuan did not even blink. Not at him. Not at the Core. Not at the godlike presence waiting.
The Core activated. Both souls were pulled into a furnace of light and pain. The Earth soul screamed; Fang Yuan did not. He watched calmly, analyzing, consuming, discarding, folding the memories into his own mind.
Demon Slayer. One Piece. Jujutsu Kaisen. Every timeline, every character, every weakness. All absorbed in seconds, cataloged, dissected, stored.
When it ended, only one remained. Gu Yue Fang Yuan. Eternal. Unyielding. Dangerous. Armed with knowledge no mortal—or demon—had any right to possess.
The godlike presence's form warped into the distance. "Your first world…" it said. "Demons and swords. Survive. Adapt. Become something even you have never been."
Fang Yuan did not answer. Words were pointless. He had no mortal friends to comfort. No goal but continuation.
The air shifted. A cold wind blew across his face. The world around him dissolved. The mountains, the rivers, the empty sky—all gone.
He opened his eyes.
The stench of blood. The smoke of a burning village. A human child crying.
And somewhere, deep in the shadows of forests and mountains, demons stirred.
Fang Yuan's lips curved slightly. Not a smile. Satisfaction. This world would amuse him. Or it would die. Either way, he would continue.
The eternal calamity had begun.