Lotor is the crown heir of Planet Doom and the Drule empire. He appeared in the 14th episode of the original series and was attracted to Allura the instant he saw her. However his evil nature repulses Allura and she rejects him often, which only fuels his obsession further to the point where he originally wanted her as a concubine, then to the point where he wanted to marry her to avoid further battle, to the point where he simply wanted her at his side. This obsession is Lotor's only major weakness because there have been opportunities where he could have destroyed Voltron if his obsession with Allura was not there.
Lotor is far more evil than Zarkon having no sense of honor or even care for his people. His Sincline counterpart is even worse to the point where he killed a member of his harem just for accidentally spilling wine on his pants and he had raped Fala's (Allura's counterpart) cousin Princess Amue and originally wanted Fala for his "collection".
In the final episode of the Beast King Go-Lion series he is killed when Ryou stabs him in the heart and they both fall to their deaths. This is undone in the Voltron series where both survive by falling in water.
- Lotor counts as both an anime villain for his Sincline counterpart and a Western animated villain because although Voltron used footage from Beast King Go-Lion, it became so popular in North America that it became a franchise, with comic books, video games, and even sequel series.