Risor was one of Quendril's assistants. He was a failed experiment to creat the perfect warrior. He wanted to warn Veltreena that Zaadur hated her. He loved Veltreena.
When Zaadur murdered Veltreena, Risor wanted revenge. Zaadur planned to conquer Earth with the Ice Warriors. She launched a rocket, which Risor stowed away on. Risor then blew the rocket up, killing himself, Zaadur and the Warriors, gaining his revenge. (AUDIO: Lords of the Red Planet)