Amber Hunt was a " typical valley girl" untill she was exposed to the Theta Virus and gained pyrokinetic powers. She discovered that she could psionically create flames by inducing spontaneous combustion and even fly by superheating the air under herself. She joined the Exiles, as "En Flame", until the damaged computer of an ancient alien spaceship, which had crashed on the moon, turned her into the "Moonchild". Amber had dormant psi-powers that allowed her to control electromagnetic wavelengths, and the alien computer, also known as the Entity unlocked those powers and used Amber to send a EMP signal over the Earth, calling all Ultras to her. Unfortunately, the EMP signal was dangerous to ordinary humans, slowly driving them insane. After an intense battle, Amber was freed from the Entity's control, and Earth was saved.
Later the Phoenix Force was pulled into the Ultraverse , and was critically damaged. Needing a human host to help heal the damage, the Phoenix Force bonded with Amber. The injury to the Phoenix Force made it insane, and Amber was unable to control it. She attacked her friends and would have destroyed the planet, if not for the arrival of the X-Men and new Ultra hero Foxfire, who after a long battle were able to separate the Phoenix from Amber and send it back to the Marvel universe.
Afterward, a portion of Amber's powers were stolen by Maxis , and her powers were greatly reduced.