Genos (One Punch Man)

Genos, or the Demon Cyborg, is the deuteragonist of the webcomic-turned manga/anime series One Punch Man. He's an S-Class hero of the Hero Association and is the disciple of Saitama, as he seeks to become stronger to kill a rogue cyborg that killed his parents four years ago. He acts as a foil to Saitama in the series.