I gave this theory in the chat right after the show tonight, but I am starting to think that Bae was Cora’s first born and Rumple took him as his form of payment for helping her spin gold. In the Fairy Tale, the woman gets to keep her child. But we all know the creators love to tweak these tales. So, because she cannot guess his name, she gives up her child to Rumple who raises him as his own. At some point Cora needs magic/power/wealth/ ect and makes more deals with Rumple. She will never be finished paying Rumple off, so when Regina kills her mother (which I think Regina HAS to do in order to become truly evil) all of Cora’s debt goes to Regina. Except in Regina we have a woman who is a match for Rumple. So they make deals with one another. Always trying to get one leg up on the other. It’s a constant power struggle for years but never fully malicious until the events of Skin Deep. After Rumple is lead to believe that Belle has died, due in part to Regina, it is a full on war and he will stop at nothing to foil her plans. Including allowing her to believe that she is enacting the Dark Curse and that there is no cure or hope for the FTL characters.