Xorn was discovered in the Dark Beast's pens following the fall of Apocalypse. The only piece of her past she has revealed is that her mutant abilities manifested during the riots that killed the members of Generation Next. She and her family were workers in the Portland Core during the riots. Upon hearing this, Magneto immediately offered her a place with the X-Men.
Xorn has yet to remove her helmet since joining the team. Some believe it is to contain her energy powers, but others in the X-Men whisper that the helmet truly hides hideous scars from her time in the Core. She has demonstrated many different powers and has admitted to both Wolfsbane and Beak that even she is surprised by her abilities.
Her dedication to Magneto's cause and her belief in what the X-Men stand for appear to be absolute. She has gone above and beyond the call of duty as a member of Magneto's X-Men and looks to be one of the best of the "new" mutants.