Heavy Metal L-Gaim (1984)

A science fiction series set in the 40th century. The setting is the Pentagona System, a fictional solar system consisting of five planets. The supposedly immortal emperor Oldna Poseidal used an elite force of Temple Knights to conquer all the planets. He then disappeared from public view, living incognito under the identity of the wealthy trader Amandara Kamandara. A mere 15 years later, the exiled prince Daba Myroad leads a rebellion by uniting various factions dissatisfied with the new regime. Oldna attempts to manipulate both sides of the war for his own reasons, but he is betrayed by his second-in-command.