Nimue is the secondary antagonist of ABC's Once Upon a Time. She is the overarching antagonist of the first four seasons and the main antagonist of the first half of season 5. She was the original Dark One who
was once the lover of Merlin before she let vengeance get the better of her and kill the man who killed her family. She follows the Darkness' plans to destroy all late magic in Storybrooke, using both Emma Swan and Captain Hook to achieve her goals.
She is portrayed by Caroline Ford.
Trivia[]
In truth, Merlin was right about Nimue helping them because she and the previous Dark Ones were absorbed on Excalibur, which Emma used to kill Hook.