Crowley\n\n Crowley was the main antagonist of Season 6 and Season 8, but he ranks at the bottom because he's quite clearly the weakest of supernatural villains. He has higher-tier demon powers, which are effective against low-rankers and human beings.

Cas had his mind entirely in season 7, he was just trying to evade his responsibilities and emotions by deluding himself and others that he wasn't that Cas who made all those mistakes, he couldn't face what he'd done, the enormity if it all when it came rushing back into his memory in one go in 7x17, so he pretended ...