Richard Pryor makes Kryptonite laced with cigarette additives that turn Superman into a jerk. That's about it. Pryor also building a supercomputer that Supermen ends up having to fight in the end. Although Reeve did make one more Superman film, I think this third entry was the real death knell for the series. As a kid, there were two scenes that stuck out for me about his movie. One, when the Bad-Superman with a Don Jonson five o'clock shadow sits at a bar flicking peanuts at liquor bottles, smashing them. And two, super villain Robert Vaughan's alpine ski slope on the roof of his skyscraper. I'd completely blocked out the ill-conceived metaphysical fight that Bad-Superman has in a junkyard with Good-Clark Kent. I'd also forgotten about the ridiculous climactic battle between Superman and Pryor's evil super computer. The Cannon Pictures sequel is what I remember being the worst in this series, but now I"m not so sure. I am a bit curious what this film might have been when I read on IMDB that the character of Mister Mxyzptlk was originally going to be in the film with Dudley Moore in the role.