Superboy-Prime

Superboy-Primewas one of the many variations of Superman in the DC universe but became unhinged following the destruction of his world and become one of the main villains of the Crisis On Infinite Worlds storyline: he had even more power than current Superman and was comparable to the Silver Age Superman in scale of power - making him easily one of the most powerful supervillains in DC comics.

Although a villain Superboy--Prime was also tragic and wasn't evil so much as a very confused and angry person - however he let his pain warp him into a monster and thus had to be stopped in order to save reality from destruction.

Powers
Superboy-Prime has had a collection of powers over time, being one of the many alternate Supermen of DC comics he possesses standard Kryptonian powers but was able to amplify them via power-armor and other devices: over the course of the Crisis Superboy-Prime became more and more powerful, at the peak of his power he had absolute control over time to the point he could create pocket universes.

Also due to Superboy-Prime being from another universe he was immune to most of Superman's weaknesses, such as magic and kryptonite - his power-suit was also designed to constantly feed him yellow sun radiation and keep him at peak power even when exposed to red sun radiation.