S4·E5 Universe of Evil

In a parallel universe, the Super Friends are supervillains, the Super Enemies. Mount Vesuvius is a focal point that links the two universes — in one universe, Superman tries to stop the eruption, while his evil counterpart is causing the same disaster in his own reality. Vesuvius explodes, causing the two Supermen to exchange universes. While Superman has to fight his evil comrades and find a way back to his own world, his evil counterpart battles the real heroes and begins his plan to conquer Earth.