Board Thread:Spoilers!/@comment-2153169-20170629021436/@comment-25375217-20170722203635

Here's an idea: the curse was cast by Drizella. Like Clorinda before her, Drizella falls in love with someone below her station - but furthermore, a woman. Lady Tremaine manages to convince Drizella that she doesn't need love, she needs money, and that if they cast the Dark Curse, they can have that. Drizella casts the curse by crushing the heart of her girlfriend. During her redemption arc, she falls in love with either Alice or Regina.