Haleena was born on the alien planet of Breakworld. She became Kruun's mate some time after he was deposed by the X-Man Colossus, and foresaw that one day the Breakworlders would be taken in by the X-Men.
Haleena was created by Kieron Gillen and Terry Dodson. She first appeared in Uncanny X-Men #536.
Major Story Arcs
After Breakworld's descent into chaos, Haleena and her mate Kruun, along with many other Breakworlders come to Earth in search of asylum. S.W.O.R.D and the X-Men allow the aliens to stay on Utopia until a permanent home can be found for them.
Haleena begs Kruun to stop after he betrays the X-Men and takes Colossus and Kitty Pryde hostage, but she is rejected. A short time later, Haleena finds Kitty Pryde after she escapes, and kills her. Haleena then immediately sacrifices herself to bring Kitty back to life, restoring her powers in the process, so that she may save Colossus. After Kruun escapes the X-Men, he discovers Haleena's body and a letter she had written to him before her death. Kruun, unable to deal with the loss, initiates the same ritual to bring his mate back. He succeeds, but loses his strength in the process.
Later, the Breakworlders are relocated to San Francisco. Haleena and Kruun remain together, and live there peacefully.