The Guy with the Secret Kung Fu (1980)

Two Ming patriots spend their days helping the weak and rescuing damsels in distress. This alum gets them in trouble, though, as they are captured and then volunteered to go after the fearsome Dragon Gang, a tribe of bandits that have been terrorizing the land. They must fight their way through the ranks, including a Taoist monk and his nearly invulnerable "demon," before they can finally face off against the beautiful and sinister leader of the Dragon Gang.