Action Comics #355

THE MIGHTY ANNIHILATOR! / THE DEATH OF LUTHOR! Karl Keller, a scientist in an Iron Curtaun country, has been held in a prison camp for years when he discovers a cache of Kryptonian chemicals that were shot into space because they were too dangerous; He experiments with them and then uses them to gain super-powers, traveling to Metropolis to challenge Superman. Luthor is accidentally killed during a battle with Supergirl, and she travels to Atlantis and into outer space to find a way to restore him to life.