Superman's Evil Persona was a separate being that was created from Superman, due to exposure to Synthetic Kryptonite which temporarily separated him into two beings. Apparently, most of his unpleasant characteristics were imbued on his evil twin, who acted without morals or care for others.("Superman III")
- This character exists in the films continuity only.
When Gus Gorman gave Superman Synthetic Kryptonite, Superman's negative personality aspects quickly became prominent, causing him to behave erratically and irresponsibly. Finally, he split into two separate beings, Clark Kent (without powers) and the Evil Superman. They battled, and Clark won, remerging with his double. ("Superman III")
In Smallville, Martha Kent used Black Kryptonite to separate his rampaging Kal-El persona from Clark, after Clark had been reprogrammed by Jor-El to act as a Kryptonian. The evil Kal-El then became a separate being, and physically fought against Clark before Clark overcame him. ("Smallville, season 4")