Super Power (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.

Unfortunately the movie Super Power is not yet available on HBO Max.