I think that he might want his powers back to help him find Bae. After he finds Bae he might not care about loosing them. I do think that he wants Emma to believe so that he can look for Bae though. He does have a lot of power in Storybrooke and cares about having that and while it isn’t magical it is still power. I don’t think he actually cares about Emma more then what she can do for him though.