41. Mongul

Question: Who managed to not only come close to defeating Superman (in Kal-El's own home, no less), but Batman, Robin and Wonder Woman as well? Answer: Mongul. Don't let the purple and awkward yellow attire fool you, Mongul is someone to tread very lightly around. He is also one whose brute strength is only rivaled by his brooding ego.

Always trying to get his hands on a super weapon of sorts, whether it be Warworld or a planet destroying death ray, Mongul has fought with Superman and murdered his way to detente rather than absolute victory. In his efforts to best those he deems beneath him, Superman has routinely become a frequent opponent.

Arguably, Mongul's closest thing to true victory came in Alan Moore's "For the Man Who Has Everything". There, he decided to end Kal-El's life on ironically his birthday, using a plant-like device to put Superman in a permanent dream state - one where the victim's vision of their ideal desires traps them in a prison of illusion. His plan would have worked, were it not for Batman & Robin and Wonder Woman's efforts. But the fact that he even tried it, let alone came this close to succeeding, is why the DCU should always fear him… even ranking at 41.