There was a villain in the My Hero Academia verse who didn’t need a flashy entrance or a mountain of power to shake society. This character first made his chilling debut in Season 2 of the series. And the moment he stepped onto the screen, his ideology changed everyone’s perspective.
Chizome Akaguro, more widely recognized by the chilling alias Stain or Hero Killer, carved his reputation as one of the most terrifying and notorious villains in the core narrative of My Hero Academia. His kill count—17 Pro Heroes murdered and 24 others permanently disabled, including the once-formidable Ingenium. His streak of victories wasn’t just because of his Quirk alone.
Stain had tremendous physical abilities that made him deadly even without depending on his Quirk. He was incredibly fast, quick enough to evade Tenya Iida’s Recipro Burst. He evaded Shoto Todoroki’s dual-element assaults—ice and flame—with precision and lightning-fast reflexes. His fighting experience and tactical ability compensated for Quirk's limitations in multi-opponent scenarios.

He has a brutal philosophy and intense presence in My Hero Academia. Stain doesn't just slash blindly. He studies his opponents, exploiting their weaknesses with surgical precision.
Stain’s Quirk, Bloodcurdle, gave him the chilling ability to freeze opponents in place after just sampling a drop of their blood. The duration varied by blood type—B-type victims suffered the longest paralysis at eight minutes. While mighty in one-on-one confrontations, this ability had clear flaws against multiple foes. Yet, he only needs a drop of blood to turn the tide of battle.
His Quirk required him to get close enough to draw blood, creating vulnerability. However, his combat training and arsenal of weapons—including a worn katana, daggers, and throwing knives—helped overcome these limitations. Even after sustaining severe injuries, he could paralyze seasoned Pro Heroes with fear through sheer presence alone.
Stain’s psychological impact in My Hero Academia

Stain's true power isn’t just physical—it's ideological. His warped vision of heroism challenges the status quo in My Hero Academia. He believes only true heroes should have the right to save others. His brutal methods spread fear, but they also sparked reflection among villains and heroes.
His presence inspired villains like Dabi and Spinner and forced the Hero Society to question its values. Even pro heroes acknowledged his conviction. His impact lingered long after he was defeated and locked away. After his arrest, Stain’s belief in rooting out 'fake heroes' rapidly gained traction, motivating many villains to rise in his name. His conviction was so intense that it created an almost tangible "aura" that could freeze opponents in fear.
Though captured early in My Hero Academia, Stain’s influence continues to ripple throughout the series. The rise of the League of Villains was heavily inspired by the extreme ideals he left behind. Characters constantly reference his name, some with admiration, others with dread.

Even after his prison break, Stain’s actions remain calculated. He doesn't act out of chaos but remains guided by his distorted moral code. He’s not driven by power or fame but by a deep belief in justice. And later in the series, Stain showed a willingness to aid heroes against greater threats. During the Final War arc, he even attempted to help All Might against All For One, demonstrating his complex moral code.
In the final thought, Stain presents a perfect balance in My Hero Academia. He is powerful enough to be a credible threat, but not so overpowered that his defeat seems implausible. Stain is a villain who fights not just with blades but with belief. And in the series, that makes him truly powerful.