The Humanoid (1979)

Hoping to overthrow his brother as ruler of the planet Metropolis, the evil Graal enlists the help of the insane Dr. Kraspin, who has invented a chemical capable of turning an ordinary person into a perfect soldier. They test this chemical on the pilot Golob, turning the unsuspecting victim into a mindless but indestructible automaton possessing superhuman strength. The people of Metropolis must somehow outwit Graal before he can create an army of these soldiers, or their planet will be destroyed.

Fantasy, Science Fiction