MTL - For My Sister, I Became the World Boss - Chapter 400

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

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?

He became Arthur. He lived his life as Arthur and claimed Excalibur.Now, he has returned with a purpose.Beneath the surface of the world lies a twisted world known as the veil—an dimension where monsters are born from corrupted human emotions and desire. The deeper you go, the more terrifying they become.Each Layer is sealed. Each hides a god-like being, waiting to rise to the surface.Now, Sylas bears the responsibility of keeping the gate between both worlds from breaking.[Keys are passed down through generations.No one knows where they came from, but those keys can open doors to another world — a world filled with deadly trials. If you complete the trial, you return with blessings from gods, mythical beasts, and ancient warriors. The amount of blessings you earn depends on how well you perform.But if you fail, the door shatters… and you are gone forever.If you survive, you are given a permanent rank — a rank that decides your place in society for the rest of your life.]

“If I were ever reincarnated in another world, I’d be the ultimate villain.”That was the last thing Ace joked about before getting hit by an out of control ambulance–ironically, while saving his best friend.Truly, Fate has a twisted sense of humor.Now Reincarnated in a fantasy world, Ace isn’t a chosen one, a prodigy, or a hero. He’s a background nobody—an extra in a story already set in motion. Weak, talentless, and scorned by society, his new life seems doomed to follow the same path as his last: forgotten and meaningless.Destined to be killed off early in the plot, With no noble bloodline, no rare mana affinity, and a world stacked against him. Ace must rise from the ashes of his failure and break this tradegy, the only way he knows how.But Ace isn’t the same person he used to be.Armed with wit, ambition, and a twisted sense of justice, he refuses to bow to fate. If the world wants a villain, then a villain it shall get. He’ll climb the ranks, topple the so-called heroes, and make sure the world never overlooks him again.This time, the extra is writing his own story and it starts with CHAOS.But as he treads the line between fiction and reality, a bigger question looms—Was his reincarnation really an accident?