Eira

Eira was a love interest of Gwaine and an ally of Morgana. It is suspected that her entire family was killed in an attack. Eira betrays Camelot and gives Morgana vital information about Arthur. She is later suspected of siding with Morgana by Gaius. She is given false information by Gwaine, and is caught relaying it to Morgana. She is sentenced to death, but pleads to Gwaine to save her. She is executed by hanging, which is seen by a heart-broken Gwaine, and a sympathetic Percival.

Trivia

 * It was rumored by fans that Eira would be a variation of Elaine le Fay. This turned out to be untrue, with no supporting basis in the show.
 * Poppy Drayton auditioned for the role of Eira, but was unsuccessful.