Speed-o’-Sound Sonic

Video Game: One-Punch Man: A Hero Nobody Knows

Rivalry in the world of One-Punch Man rarely gets more personal than it does with Speed-o'-Sound Sonic. As one of the first confirmed playable fighters in One Punch Man: A Hero Nobody Knows, this cold-blooded ninja carries his obsessive grudge against Saitama directly onto the battlefield, making him both the game's standout villain and its most compelling competitive pick.

Speed-o’-Sound Sonic’s Personality and Fighting Style

Forged in the brutal curriculum of the Ninja Village as a member of the 44th Graduation Class, the group ominously nicknamed “The End,” Sonic walks through the world with absolute contempt for everyone around him. His ego is not mere arrogance; it is the bedrock of his entire fighting philosophy. Calm on the surface, he is driven by a burning internal need to destroy any opponent who has ever bested him, and Saitama, the one man he simply cannot beat, has become a permanent thorn in his pride. In the game, that intensity translates directly into a mobility-first playstyle built around Ninjutsu, relying on blinding speed, katana strikes, and explosive shuriken to dismantle opponents before they can react. His Killer Move “Wind Blade Kick,” a spinning momentum-launch attack, captures exactly who Sonic is: someone who winds up everything he has and throws it at a problem without hesitation.

Who Voices Speed-o’-Sound Sonic in One-Punch Man: A Hero Nobody Knows?

Erik Kimerer brings Sonic to life in the English version of the game, reprising the role he has held across the full One-Punch Man anime run. Kimerer is widely recognized in the dubbing community for his work as Ryuji Takasu in Toradora! and Obanai Iguro in Demon Slayer: Kimetsu no Yaiba, and his ability to blend icy menace with barely restrained aggression makes him a natural fit for Sonic’s particular brand of focused malice. On the Japanese side, Yūki Kaji voices the character, the same performance that originated the role in the anime. Kaji is one of the most prominent voice actors in the industry, celebrated for his work as Eren Yeager in Attack on Titan, and he brings that same combustible intensity to Sonic throughout the franchise.