Board Thread:Show-Related Questions and Answers/@comment-24723109-20140322235700/@comment-24674051-20140323013357

I agree with the original post. I think Zelana has the Dark One's dagger. With that, she can control Rumple, and have him do anything. Since we know that Rumple created the original curse, and the nature of the curse was such that it took him a long time (read probably more than a century) to research and produce, it is unlikely that anyone else can come up with anything even close. So it is at least a fair guess that Rumple is the caster of the new curse (albeit at the behest of Zelena). Also, we know that the curse requires the sacrifice of the person that the caster loves most. Regina had to sacrifice her Father, Pan sacrificed Felix. So Rumple had to sacrifice someone, and that someone is most likely Baelfire. And because this was forced on him, it would indeed likely drive him almost to the point of insanity.

I also think that it was Rumple that sent the message to Hook. He has some free will (at least prior to the curse and his insanity), and he probably built a couple of loopholes into the new curse, which could be identiifed by Belle, and then exploited by the original Saviour (Emma).