Morgana Pendragon

Morgana Pendragon was the biological daughter of Uther Pendragon and Vivienne, the half sister of Arthur and Morgauseand the adopted daughter of Gorlois. Originally a kind-hearted individual, Morgana turned evil after being corrupted by Morgause and being betrayed by her friends. After that she betrayed her family and friends, even being involved in the death of her own father. She is determined to take over Camelot and will allow nothing to stand in her way.

The Protectors of the Multi-Universe
Morgana killed her half brother and his wife, then took over his kingdom in Camelot. She is also Abigail's aunt.