David, at a young age, was living with his mother and stepfather in Paris when his home was attacked by terrorists and his stepfather killed. The trauma of the situation caused an initial manifestation of David's mutant powers, as David incinerated the minds of the terrorists. In the process, he unintentionally absorbed the mind of the terrorist leader, Jemail Karami, into his own. Being linked to so many others at their time of death, David was rendered catatonic for years. As he slowly recovered, he was moved to the care of Moira MacTaggert at the Muir Island mutant research facility. The trauma (possibly in conjunction with the nature of his reality-altering powers) had caused David's psyche to splinter into multiple personalities, each personality manifesting different mutant abilities.