As for the Rumple factor, that’s an interesting way to look at it and not one I’d stopped to consider. But, I guess the question I come back to is…is there really hope for the “devil” after everything he’s done. Lucifer isn’t forgiven; he’s cast into a pit of fire and brimstone (in Rev.)
I think the devil in this case would be whatever the original Dark One power is, and the people whose names are on the dagger are just those who have believed the lies of that dark power. The devil himself doesn’t become a prisoner until the very end of the book. (Just to put my cards on the table face-up, I’m from a quiet fundamentalist denomination. I don’t want to annoy anyone.)
That’s not a bad idea! Destroy the power, without destroying the man. Rumple is left human again, I suppose, and his S5 arc is really about finding his way back after so much darkness. It would still be a “death” but not a literal human dying–just Emma vanquishing darkness. My only qualm is Belle’s role in all this since her TLK (and her status as the Beauty to the Beast) is supposed to do that particular deed. Belle would help him redefine his humanity post-destruction of DO’s power, but I could see some…people…*cough* shippers *cough* being pretty upset that Belle didn’t break his curse with TLK.
Not that A and E necessarily have to play to their shippers.