User blog comment:Fusedtwilight/Season 9 plot/@comment-86.154.74.121-20130518194117/@comment-1509826-20130518211709

I don't think Eve had a soul, she was described (by the produces) as closest to a deity and as far as we know they don't have souls, so she wouldn't go back to Purgatory she would simply fade, so the dragons are unable to fix her. If she did have a soul, maybe now the persecution of her kind has stopped, she's desided to simply leave things as they are, that was what drove her out of purgatory in the first place.

As for the Leviathans, as Crowley put it they only had one king, with Dick dead there no longer able to function in groups, as such any chance of them getting Dick out is at best unlikely. Not to mention Crowley and his army of demons presumably managed to put the majority of them out of action.

From what the shows shown, Demons adn Angels just fade away into nothing, they may have some place, but so far it seems they just fade.