Board Thread:Spoilers!/@comment-24674051-20150626172312/@comment-26901329-20150721090707

I have a theory: Cora wanted to become the DO, so she did some research in Camelot. She found Lancelot and used the gountlet to find his weakness, Guinevere. She said that if he helped her learning more about Merlin and the origin of the darkness she would make a love potion. Lancelot who knows not that much about magic beleved her. When cora has done enough research and she is ready to go home Lancelot comes and tries to stop her, for he never got his love potion. She killed him, Rumple came and he wanted the gountlet, but he had to make a deal to get it and he gives Cora the long staff she used to created the shield to protect her corner of the land from the curse. When Cora came to SB she knew that the DO after Rumple wouldn't become the DO but rather a  vessel consumed by the darkness. She though it was so importand to get the darkness before Rumple died because she can't thether it to her own soul, only the savior can.