Superman Spectacular #1

Terra-Man discovers kryptonite in the asteroid belt and offers to share it with Luthor to destroy Superman. When Terra-Man attacks Superman, Luthor is shocked to learn it is red kryptonite, which has unpredictable effects on Kryptonians. It causes Superman to split into two bodies, one with a red costume and one with a blue costume. Later, Luthor reveals to Terra-Man that he has succeeded in opening a rift to another universe where magic dominates over science. He creates a device to control that magic. After Superman's two bodies merge back into one, he defeats both Luthor and Terra-Man.