Billy Kane is one of the villains from Fatal Fury.
Billy and his sister Lilly were orphans in London. They both lived a poor life, with Billy having to look over his sister while trying to find some decent job. He eventually finds a job in a factory in Southtown, but this changed little his life. One day, unable to bear that humiliation anymore, Billy went crazy, taking an iron tube and beating everyone in the place. At that exact time, the owner of the factory was paying a visit and witnessed the entire scene. Billy was already expecting the worst, but the man, Geese Howard, was really impressed, and offered Billy to become his bodyguard and right-hand, while he would pay him to train fighting. Billy couldn't believe, accepting the proposal. Billy became a master in Bojutsu (fighting with a staff), serving Geese as his most trusted henchman. Geese hosted the King of Fighters tournament every year, deciding to enter Billy in the competition in order to keep anyone from winning the tournament, remaining the undefeated champion for years. Billy was defeated in the tournament by Terry Bogard, who wanted to take on Geese. After Geese is defeated and is apparently dead, Billy returns to England. He is invited by the heir of the Stroheim family, Wolfgang Krauser, to be his bodyguard and enter his now international King of Fighters tournament. Billy accepts the offer, but he actually was undercover to investigate Krauser and to find a Geese impostor. After Krauser's defeat, Billy returns to his job as a bodyguard of Geese, who was now healed. Geese sends Billy to defeat Terry Bogard when he decides to fight Geese and stops him from reading the sacred scrolls he stole. Billy is once again defeated, and Geese dies definitely. With Geese's death, Billy once again returns to London to take care of his sister.
Billy isn't really an evil person. He has a strong sense of loyalty and gratitude towards Geese not to mention that he is mainly doing crimes just to make money to provide for his sister Lily. He also despises traitors and anyone who insults Geese, but what he really hates is cigarettes, attacking anyone who smokes in front of him.