Board Thread:Spoilers!/@comment-26612471-20150709135348/@comment-24674051-20150709170506

And in speaking of a different spin, here's a random, speculative thought.

Morgana was not originally a dark sorceress, but was in fact Merlin's lover and associate. She was almost as powerful as Merlin, and together, they had been researching the darkness and how to stop it. At the time, Merlin had the idea of tethering it to a human soul in order to control it, and he and Morgana worked on the Dagger together. However, Merlin was planning on sacrificing himself to tether the darkness. Because of her love for Merlin, as well as her respect for his power, Morgana willingly gave herself up, grabbed the dagger (in much the same way as Emma), and sacrificed herself.

That also explains why Merlin created the Hat, and has continued to search for a way to completely destroy the darkness. He is single minded in his pursuit of destroying the darkness.