Which DC super villain would defeat all the other DC supervillains in all-out battle?

Question

The ones that are still alive in DC continuity. From "this" Earth. Tell me why for your answer.

Answer 1

Doomsday,

He put the Blue Boy Scout in the grave, and cannot be 'killed' the same way twice. His biggest challenge from the Villain community might be Lobo (assuming he's still a Villain) or Parasite, who could arguable drain everyone dry, then use that strength to dispose of the bodies so if or when any one survived he'd be established as Top Dog, and no one could usurp him.  

Answer 2

...Deathstroke the terminator aka slade wilson or Slade in the teen titans tv show

Answer 3

Superboy-Prime possessed just about the same powers as his counterpart Superman although they appear to be more powerful due to his insanity.  Superboy-Prime's power levels are reminiscent of the powerful Silver Age Superman, accomplishing such feats as overpowering two Supermen and defeating or killing many other DC heroes.  Superboy-Prime also wears a yellow sun powered suit of armor to further enhance his power.  His body is currently energized with energy from Ion and an Oan, the energy will eventually leave him, but what he can do with his powers until then is unknown.

    * - Flight

    * - Hearing – Prime hear anything, anywhere like the Silver Age Superman.

    * - Healing Factor

    * - Heat Vision

    * - Invulnerability –  He can fly into a sun unharmed like the Silver Age Superman.

    * - Mental Powers-Prime has Silver Age Superman's powers to learn. He learned every Earth languages and 28 alien ones.

    * - Super Breath – He can create hurricane, freeze foes or blow out stars.

    * - Super Hypnotism - He has Silver Age Superman's hypnotic skills

    * - Super Strength – He can move planets.

    * - Super Speed – He can travel faster than the speed of light or cross the time.

    * - Super Ventriloquism - Prime has Silver Age Superman's ventriloquism powers strong enough to speak to other contents.

    * - Vision powers –  Prime has x-ray, microscope vision and telescope vision that was strong enough to see across universes.

Answer 4

Two come to mind who could be used in such a storyline: Lex Luthor and Darkseid. Luthor, of course, has no real powers but has been a thorn in Superman's side since 1940; for the past few decades, since Luthor was reinvented by John Byrne as the head of an enormous corporation, he has gone from being "a mad scientist" to being a master manipulator (capable of manipulating his way into the Presidency, for example) and he could be used in a scenario where he defeats all (or probably just most) other villains for some sinister, secret reason.

Darkseid has generally been presented as the ruler of an entire corrupt and evil world, and has many minions who have great power, and Darkseid's "omega-beams" make him more than a match for any DC hero, but it is his quest for the "anti-life formula" that potentially raises him head and shoulders above all other DC villains. If Darkseid had the secret of the "anti-life formula" he could either rule or destroy the entire universe, which would be a hard act to follow.

Naturally, Luthor would only be able to defeat all (or most) other DC villains by using clever plans, pseudo science, and minions, and wouldn't triumph in any scenario where someone gathered all DC villains together to fight and said "Go." Darkseid, however, might be the last person standing in such a scenario.