Back in Season Three, when Rumple sacrificed himself to defeat his father Peter Pan, he went to the underworld where he meets (or sees again) Hades. In a recent episode, Hades tells Rumplestiltskin that he wants him back up there killing people and delivering their souls to his underworld.Â
My theory is that Hades met with Zelena at the start of Season 3B where they planned the revival of the dark one so he can continue giving Hades the lost souls of the people he kills. It was Zelena who put Lumiere up to the job of resurrecting the dark one via Hades. Would the Wicked Witch of the West really have knowledge of the dagger and resurrecting a Dark One without speaking to a god who knows everything such as Hades?Â
A couple things I can think of as to why she agreed to resurrect him would be to: enslave a dark one to do her will (obvious reason), and the other one would be the spell/formula to make a time portal.
Thoughts?