Wu zhuang yuan (1980)

A dying Manchu kung fu fighter sends his three sons on a mission of revenge against the five Southern champs who defeated and humiliated him a generation ago. The three Manchus enter the town where the old champs live and begin challenging and fighting an unprepared group of once-powerful martial artists and their sons. After his counterparts in the other families take some serious beatings, Billy is forced to take a crash course from a noted teacher in North and South Eagle styles as well as Horsehead Fist. Only then is he able to confront each of the three Manchu fighters.