Psi (comics)
Psi is a DC character created by Paul Kupperberg and Carmine Infantino for Daring New Adventures of Supergirl #1 (November 1982).
Fictional character biography
Her real name is Gayle Marsh. At the age of twelve, she developed psychic powers, primarily psychokinesis. After her parents died she was raised by the scientist David Pendergast who was preparing to fight a new menace called "the Decay." In college, she took the alias of Psi and fought Supergirl several times, thinking that Supergirl was the Decay. The truth was that David Pendergast was an extension of her own fears. Realizing that the Decay was David and herself, she put a stop to Pendergast and herself.
Later she joined the Suicide Squad for a mission in Central America, but she was killed by the Rocket Red Brigade. Her allies, Mister 104, the Thinker and the Weasel do not survive the mission.
During the events of Blackest Night, Psi's corpse is reanimated as a member of the Black Lantern Corps alongside several other fallen Suicide Squad members. Psi is apparently destroyed by the Manhunter's self-destruct mechanism to unleashing an explosion of Green Lantern energy that eradicates the Black Lanterns.