Ray

The Ray was a member of the Justice League after the Thanagarian invasion.

Background information
The Ray both appeared several times on Justice League Unlimited and was referred to by name on one occasion, but it wasn't until the release of a Mattel action figure identifying the character as the Ray that his identity was confirmed.

In the DC Comics, Raymond Terrill was told by his supposed father that exposure to direct sunlight will kill him. At the age of eighteen, Ray learns the truth about his heritage while at the deathbed of his father, "Happy" Terrill; the dying man admits that he was the original Ray, and that exposure to sunlight will activate Raymond's own light-based super powers. As a child, he would have been unable to control such power, and thus had to be kept in darkness. At the funeral for "Happy" Terrill, Ray meets his cousin, Hank, who urges him to become a super-hero like his father. When he refuses, "Happy" shows up very much alive, in his classic Ray costume and looking far younger than he should, to meet his son. He tells Raymond that he was in fact raised by his uncle, Thomas Terrill, and that he must use his newfound powers to save the Earth from a powerful cosmic light-entity. Raymond eventually decides to take up the mantle of "The Ray", defeats the evil Dr. Polaris, and succeeds in dissuading the light entity from its destructive purpose.

Ray's adventures eventually bring him to join the Justice League and he is now a member of The Freedom Fighters