Board Thread:General Discussion/@comment-25349018-20160108055126/@comment-24674051-20160304180125

Well, since the arc has not aired, I don't think we can include Hades, since we have no clue as to how evil he will be, or if he is even the villian. (My guess is he is)

Cruella was definitely a psychopath when she was alive, and is #2 on my list. But I think the worst villain (or maybe stated better, the best villain) is Rumple. Sure he's had his seemingly bright moments, but his manipulations, lies, deceit, and murder put him in a league of his own. After 4 1/2 seasons, he has had only 1 arc where he was even remotely non-villainous (the NL arc), and even then he was selfish, and his actions were not as much heroic (except the final sacrifice) as much as self-serving.