Superman III

The third Christopher Reeve-starring Superman movie sees the Man of Steel battle elements of himself as well as a computer genius (Richard Pryor).

An evil CEO with plans for world domination manipulates Gus Gorman (Pryor), using his computer skills to control satellites, steer stolen missiles, and create a synthetic Kryptonite to kill Superman. The resulting concoction turns the Man of Steel evil - he's got a bad attitude, gets drunk, and generally wreaks havoc around the globe. Eventually, bad Superman splits in two – good Clark Kent and evil Bizarro. The two entities of equal strength battle it out while a showdown with Gorman's super computer awaits the victor.