Two-Face

Harvey Dent was born in a lower-class family and had a developed a slight hatred of upper-class people. He rose to become district-attorney and became a friend of Batman. However, this ended when crime boss Sal Maroni threw acid into his face during a trial, horribly scarring him. The left side of his face was permanently disfigured, and the deformity drove him mad. He eventually became a criminal and renamed himself Two-Face. Two-Face would make his choice to kill or spare someone based on a coin, with one side of it also being deformed by the acid. He would flip the coin, and if it landed on heads, the undeformed side, he would spare the victim. If it landed on the scarred side, however, he would kill the victim.

He was sent to prison but later escaped, now insane with anger and revenge. He blamed Batman for his disfigurement despite it being Sal's fault, and Batman has been forced to fight him numerous times.