In and out of boy homes from the age of 8 Mentallus managed to escape when he was 15 and join an underground super villain group in the city. Working up toward a big day his super villain group set about a master plan to rob all the banks in the city at once and teleport to another dimension.
Alas they were stopped and during the battle Mentallus suffered such traumatic mental feedback it essentially put him into a mobile coma of sorts. Not knowing who he was or capable of feeling emotion anymore he was recruited by the authorities under a new ID and new concept: to help others. Given a mask and new costume he now patrols the streets fighting for good. The authorities hope he never remembers who he was.