A rare omega-level mutant, the 16-year old girl known only as Malice's powers began to manifest at only two years old, when during a crying fit, she caused her mother, then her father, to collapse in excruciating pain, clutching their heads in agony.
Sensing this with Cerebro, the villainous Charles Xavier had the girl abducted and brought to him, where he raised her in a cruel, strict manner, teaching her to embrace sadism and making sure that she never knew her real name, 'Malice' being the only name she's personally ever known.
Xavier used her a weapon, bringing anyone he needed to get information out of to her, where the girl would cause them severe pain, sometimes to the point of death, to get anything out of them that Xavier wanted.
Her destiny began to change when the X-Men captured one of Magneto's younger charges, a girl called Wallflower. Xavier wanted to know where the Brotherhood was hiding, and told Malice to do whatever it took to get the information from her. But no matter what she did, Wallflower seemed to pity her, more than fear or hate her. Realizing this was a good, decent person she was torturing, Malice stopped just short of getting the information from her, and 'accidentally' passed out from using her own powers too much, giving the other girl a chance to escape.
Since then, Malice and Wallflower have met in battle several more times, each time ending with Wallflower trying to convince Malice of the good that's in her, and Malice eventually deciding she could never be a hero and leaving with Xavier.