Complete Monster: Zygon, a smug, domineering galactic conqueror with a God complex who seeks to enslave and rule humanity. Formerly a rogue android known as Nexus, his first attempt to take over humanity was stopped by guardians known as the Ka-Khan, and his army was destroyed. Forced to hide, Zygon bides his time and establishes a slave mine on the planet Zinia, forcing human slaves (who are forced to work regardless of age or physical condition) into such harsh conditions they often die. The blade the Ka-Khan used to defeat him is found by an old slave, who's killed to keep it a secret. Once Orin finds out about the blade and decides to escape, Zygon fatally strangles his girlfriend Elan. After Orin escapes, Zygon places a massive bounty on his head and has his Mecha-Mooks attack him at every turn. He captures Dagg and has him slowly and painfully tortured by shooting a laser into his forehead, overseeing it with a sadistic grin. After he has the heroes within his grasp, Zygon leads his ships to obliterate the human's opposing fleet and take over the planet by force. Once he's been revealed as Nexus, Zygon takes Aviana (the new love interest) hostage, threatening her life. Once Orin surrenders, Zygon attempts to strike him down with his own blade. Cocky and arrogant, Zygon was as remorselessly cruel as an evil overlord could be.
Crosses the Line Twice: The infamous re-programming scene. As if kidnapping a sentient robot and re-programming her against her will wasn't enough, her personality circuits are located in her behind for some reason. Dagg is delighted finding this out and Silica start screaming for help before he gags her with a tape and proceeds the operation.
Also, the blade being invisible on the hilt of the sword brings a certain famous sword to mind.
A hero who came from underground who later breached the surface and still later fought the alien overlord with the artifact? Hmmm.
Memetic Molester: Dagg, largely due to the re-programming scene. The Jabba expy implying he's a pedophile certainly doesn't help.
One-Scene Wonder: The Man-Droids are one of the few original elements in the film. They're placed in a fitting enviornment that gives a genuinely spooky atmosphere. They appear in only one scene, barely mentioned in the next, and never again.