Garō, a former martial artist turned self-proclaimed villain known as the Hero Hunter, seeks to become the ultimate monster by defeating heroes. Childhood bullying fueled his resentment toward societal biases favoring popularity and conventional heroism. He admired monsters as underdogs, rejecting the narrative of heroes always prevailing. Trained by master Bang, Garō was expelled for violently attacking fellow students, solidifying his monstrous path. He stalks heroes across threat levels, viewing each battle as a chance to evolve his combat prowess. His physical transformations escalate from minor mutations—claws, fangs, hardened skin—to a Complete Monster form with armor-like physiology and enhanced strength. Despite his monstrous appearance, he adheres to a moral code: avoiding killing heroes or civilians while protecting the vulnerable, particularly a boy named Tareo whom he repeatedly rescues. This protective instinct contradicts his proclaimed villainy. Exposure to cosmic entities unlocks an Awakened Cosmic Fear Mode, granting abilities like gravitational manipulation, energy projection, and space-time traversal. This form emits lethal radiation. Facing Saitama, Garō copies his techniques but is outmatched. Saitama deduces Garō's underlying desire to be a hero, exposing his monstrous persona as a facade. Defeated, Garō faces a crisis of purpose. When his radiation poisons Tareo, he manipulates time to reverse the damage, sacrificing his power to save others. Post-defeat, Bang imprisons Garō, who remains conflicted about his identity. He rejects binary good and evil concepts, yet his actions suggest lingering altruism. His development concludes ambiguously, unresolved between destructive goals and protective instincts. Adaptations vary: the manga amplifies his accidental heroism and deepens his bond with Tareo, while the webcomic maintains a more consistently antagonistic portrayal until confronting Saitama. The manga renders his Monster form temporarily feral; the webcomic preserves his sanity throughout. These differences highlight divergent narrative emphases while converging on his core arc of seeking power to challenge societal injustice.