From Mortal Kombat?

The flash

He’s not a villain.

The Joker

Red Hood technically isn't a villain anymore. So he doesn't count

Yeah, but you can pick him when he WAS a villain.

@Cliff1647

No, the leader of the Kobra cult in DC

Oh, him. Hmm, interesting choice.

Joker

Darkseid (but make it a fair fight)