Nemesis

Isabel St. Ives, a.k.a. Nemesis, (voiced by Colleen Wheeler) is the daughter of "Deadly" Ernest St. Ives, and used a magical sword "scarcely an atom's width thick," allegedly the only weapon capable of killing her father, to assist the Canadian superheroes, Northstar and Aurora in combat with him. Although she apparently killed Deadly Ernest, he did return.