Mordred, son of Morgaine
Mordred is the son of Morgaine, and he believes that the throne of Arthur's kingdom should rightfully go to him. He has deep-seated resentment for King Arthur, but especially for one of his knights of the famed Round Table, Sir Galahad.
His extreme irritation at Galahad prompts Morgaine to summon Dhiar for assistance. Although the Incubus does resolve the situation, he does it in a way no-one could possibly have anticipated.