Prison Planet (1992) on Netflix

Plot summary

By the year 2200, an evil king rules over Earth, and a small band of rebels is the only force left against him. Blaine, one of those rebels, is committed to overthrowing the tyrant, and he arranges to be arrested so that he will be sent to Prison Planet, an inhospitable wasteland. He goes there to find the true ruler, the king's brother, and Himshaw, the man who can restore peace and justice. The planet is protected by a brutal warlord and by warriors as sadistic as he is, and violent goons stand between Blaine and what he has come to find.