Transmigrated extra with mangakyo sharagan : rewritten

When a terminally ill young man awakens in the world of his favorite childhood game, he realizes he isn’t the protagonist, the destined hero, or even a major side character. Instead, he has become an extra—a disowned noble barely clinging to relevance in a world where strength determines everything. Worse, his fate in the game was to die an early, meaningless death.

Armed with only his knowledge of the game’s storyline and a common system that tracks his stats and skills, he is determined to survive. But mere survival isn’t enough. He remembers a hidden easter egg from a long-forgotten anime collaboration: the Mangekyō Sharingan—a power limited by game mechanics but unrestricted in reality.

With Kamui as his trump card, he walks the fine line between fate and freedom, seizing power from the shadows while avoiding suspicion. As the protagonist and his allies battle against demons and unravel the game’s grand destiny, he secretly builds his own strength—manipulating events, mastering forgotten arts, and even forging ties with villainous factions.

Will he remain a footnote in history, or will he carve his own legend in a world that was never meant to be his?