Billy Hao was a lawyer who planned to stop the reign of his brother, Robert aka Chaka Khan, leader of the criminal Golden Tigers gang. He was brainwashed by his brother into taking his place as Chaka Kahn and fighting Iron Fist. During the battle, Robert struck Billy with his electrified nunchucks, apparently killing him and framing Iron Fist for his murder.
The NYPD kept his survival a secret in order to draw out Chaka Khan while Billy gave all the information about the Goolden Tigers to the police. After Iron Fist defeated Chaka, Billy revealed himself, as well as the fact that the brainwashing had reawakened his martial arts instincts, enabling him to survive Robert's blow.