Superman-X was a clone of Superman created in the 41st century to fight Imperiex. To eliminate his primary weakness, the clone's DNA was spliced with Kryptonite, not only making him immune to Kryptonite radiation but giving him new powers that Superman didn't have. Despite all his power, Superman-X was unable to defeat Imperiex, so he used a time machine to travel back to the 31st century to recruit the Legion of Super-Heroes. With their help he was able to finally defeat his mortal enemy.
In addition to having the normal Kryptonian powers of superhuman strength, super-speed, flight, and invulnerability, Superman-X has Kryptonite blasts, green energy blasts he can release from his hands that form Kyptonite crystals around anything they strike. He also can create energy shields from the back of his hands that can block attacks, and can also function as energy blades.