For ten years, he played Boundary of Ruin. And for ten years, nobody managed to defeat Pride, its strongest raid boss.

Then the servers shut down, and he woke up on an operating table.

He is Leaf, Specimen No. 7, one of the children being tortured and transformed into the very demon king he had spent years trying to beat. With the child's memories, a status window, and the abilities to adapt and evolve, Leaf has one goal: survive the experiments without losing himself to the monster they're trying to create.

He escapes the laboratory, but escaping the game's story is another matter. Every major change earns him Causality Points, and the world he knows is beginning to diverge from the one he remembers.

Armed with knowledge no one else possesses and power that keeps growing, Leaf makes his way through a world of martial arts, monsters, and academy rivalries. At Daehan Academy, he crosses paths with Mikaru, the game's saintess, whose life is already heading off-script.

Leaf is becoming the strongest raid boss the game has ever known. The question is whether he can become that powerful without becoming Pride.