Board Thread:Character Discussion/@comment-27255668-20151210232252/@comment-26116863-20160318031335

He may have been in a seperate section of the underworld. Hook was in a special dungeon. And we know that Rumple may have made some sort of deal with Hades. Maybe Megera, Hook, and Gold all sold their souls to Hades to be given up when they died. This time he came down while still alive, so he was able to roam more freely.

He was talking about turning her dark, and your explanation would make more sense than the storybook revision requiring dark savior blood plan, which he seemed to just be making up as he went along in a very uncharacteristic fashion. The writers sometimes try to clean up messes by retconning (eg. Regina killing Marian), so this would be a good way for them to explain away his cartoonish behavior. He was cleverly diverting them away from his real plans.