Personal Info:
Real Name: Gayle Marsh,
Also Known As: No known Alias
Place Of Birth: Skokie, Illinois
First Appearance: Supergirl Vol.2 #1 (1982) Bronze Age Villain
Known Associates: Daniel Pendergarst
Group Affiliation: Formerly Suicide Squad, Council, Black Lantern Corps
Base Of Operations: Chicago, Illinois
Grudges: Supergirl
Creators: Paul Kupperberg and Carmine Infantino
Mental Powers; Psi has vast psychic powers, she has demonstrated: Telekinesis, Telepathy, Flight, Power Absorption, Energy Absorption, Energy Projection and Teleportation. Psi is so powerful and sensitive that she can't block other people's emotions and feelings properly. Often she feels someone else's pain, hatred as if it was her own.
Gayle Marsh, a powerful psychic born in Skokie, Illinois. Gayle was found by Daniel Pendergarst, who spent years training her and indoctrinating her into believing the sorry state of the world was due to the influence of something he called the Decay, and she was the one destined to cleanse the world from it... but it'd demand a big sacrifice. Gayle was unwilling to slaughter people for the greater good even though Pendergast insisted it was inevitable.
Gayle happened upon Linda Danvers (Supergirl) by accident, and sensing her huge powers, thought she was an agent of Decay. Gayle warned Pendergast, who freaked out and decided to push forward his plans, sending Gayle to attack Danvers.
Psi at DC Database