Bio: Hro Talak is the leader of the Thanagarian forces and is
also "promised" (engaged) to Shayera Hol (Hawkgirl). In an attempt to
build a hyperspace bypass on Earth, allowing them to strike the home
world of the Thanagarians sworn enemy, the Gordanians, Hro Talak found
that taking over Earth wouldn't be as easy as he had thought. Facing the
opposition of the Justice League and Hawkgirl, Hro was eventually
defeated and forced to leave Earth, but not before breaking up his
relationship with Hawkgirl and her relationship with Green Lantern.
For more, refer to the Justice League Unlimited bio.