Isillia was one of the Caerlinn sisters. She did not enjoy the political scene, and preferred to wander off on her own. Growing up, she often find herself to be a troublemaker who would cause much distress for her family.
During the party's encounter with the Caerlinns, Isillia revealed herself to be a lycanthrophy who could take the shape of a wolf. She was vicious and bloodthirsty, and had to be knocked unconscious for the combat to end.