How not to be Multiverse Mercenary

In his previous life, Leo was confined to a bed with a terminally ill body, brimming with talent but completely immobilized. Tragically, he couldn't even fulfill his passion for firearms.

After enduring a life filled with suffering, he was reincarnated into a new existence. Driven by an intense lust for guns and marked by immaturity, he carelessly navigated his new life, which led to disastrous consequences: he lost his left arm and an eye. Just when it seemed his fortunes could not worsen, an opportunity emerged in the form of a cliché system.

This system presented Leo with a critical mission: he was required to travel across various anime and movie worlds to eliminate other Isekai protagonists. His task was to correct the anomalies disrupting these worlds to prevent cataclysmic interference from outer gods. This mission not only gave Leo a chance to engage his gun fascination but also provided a pathway to potentially redeem his tumultuous past.
Main world:
Black Lagoon
Nisekoi
Jormungand
Traveling worlds:
One Punch Man
Fairy Tail
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English isnt my main language and if you are looking for Gary Stu type of MC then it is not for you. It is comedy, harem and action. Harem being undecided for the time being.