Interesting how she became the Dark One to protect someone she loved (Regina) and embraced the darkness to save someone she loved (Hook).

^

But I still don't like how it's all so CS heavy.

Yeah, the whole Captain Swan thing always makes me GAG! Besides, it really infuriates me that she did all of this to save his life and to get rid of both of their darkness (whether or not she went the right way about it), he says he wants to hurt her for saving his life and keeping him from embracing the darkness by embracing her darkness. He's a real ASSHOLE! I mean, Emma hurt Henry and Regina didn't plan on hurting her (since she cares more about someone hurting Henry than she does someone hurting herself) and instead uses her own experience to give helpful criticism. Also, I'm curious, how did Hook not have the voices of the Dark One inside his head like Emma did, since he didn't embrace it? Also, how the hell is he the Dark One if Emma gave him Merlin's power? Shouldn't he have Merlin's light magic or something? I sure hope they explain all of this in the next episode.

Katara, Merlin had the same magic as The Dark One, but as he was chosen by the holy grail, he had the power to channel that into light magic, but as he explained to Nimue, only he is capable of controlling it. As the magic that saved Hook was dark magic, that's what would've transferred to him.