Nightfall is a member of the Cadre and a minor league opponent. Her bracelets giver her ability's such as Darkness Manipulation and Flight. Her Darkness absorbs all light near it and all kinetic energy. There isn't much known about her or her Team outside of fights. Nightfall seems to be one of two surviving members of the original Cadre.
She later appeared in the show Justice League Unlimited as a member of the Legion of Doom.