General zod appears as a warlord from krypton who was Able to survive the destruction of his home planet. Now he is obsessed with destroying the Earth to turn it into a new krypton, or just for fun. Since he is also kryptonian, he has the same powers as Superman, so his threat to the world is more than real.
ZOD
Lex
All of the above villains were either born with their abilities or received them later, and Lex Luther never had any superpowers other than wealth. Lex is Superman's worst enemy, as Luthor considers Clark the greatest threat to humanity. Lex can't get over the fact that people worship Superman as a God. He believes that sooner or later humanity will have to pay for such a naive belief.
Luthor
JOHN
John Corben was a con artist who almost died in a car accident. Scientist Emmett vail saved his life by placing Corben's brain in a robotic body powered by kryptonite. Vail ordered John to kill Superman, but instead of following orders, Corben killed Emmett. John, now known as Metallo, began using his body to commit even more crimes and eventually he attracted the attention of Superman. Due to kryptonite fueling the Metallo robotic body, Korben has been a serious threat to Superman for decades.