Two Pokemon. Zekrom being the embodiment of Yin, which is generally associated with all things dark and evil, and Darkrai being the embodiment of nightmares, as well as showing plenty of evil in Pokemon Mystery Dungeon 2.
- Who has a better appearance?
- Who is more useful in combat?
- Who's more evil?
I'm going for Darkrai for this one. He's my favorite Pokemon of all time for a reason. He has an appearance that exudes an aura of malevolence, and the good ol' Dark Void + Nightmare + Bad Dreams + Dream Eater combo works wonders. And Darkrai is definitely more evil than Zekrom.