White Comanche (1968)

William Shatner plays two roles: cowboy Johnny Moon and his ruthless Indian twin brother, Notah. Notah likes peyote and gets the crazy idea that he's the Comanche messiah sent to lead the Comanche nation against the white man but more specifically the dusty desert town of Rio Hondo. Moon, estranged from his brother, decides to stop Notah either by words or by bullets.