Celtic: A devolved form of the goddesses The Morrigan, Modron, or Badb.

'The Lady of Avalon'. She tends to Arthur when he is wounded. He character is later blackened and she is seen, in some versions, as a woman with magical powers, trained by Merlin, but using her magic for bad rather than good. She is sometimes said to have a son, Yvain.

a wicked fairy who was the half sister of King Arthur

Welsh. Death Goddess. Glamorgan in Wales is her sacred terrotory.

In Arthurian legend, Morgan le Fay, alternatively known as Morgaine, Morgain, Morgana and a slew of related name variants, is a powerful sorceress and sometime antagonist of King Arthur and Guinevere.

Ah! My Goddess The Movie. She was the Fairy Princess, and Celestin's coconspirator.