Xavier's dark side is the part of him that would use his powers for personal gain and conquest...the "Mr. Hyde" to Xavier's "Jekyll." Xavier consciously kept his dark side under control at all times.Shortly after Moira MacTaggert's arrival at Xavier's School, she gave him a sedative to help him with the severe psychic distress he was suffering due to his initial psychic contact with Lilandra (though at the time he knew not the source). With Xavier's psychic defenses weakened, his dark-side gained freedom. It generated psychic constructs of four of the original X-Men (Angel, Beast, Iceman, Marvel Girl) and sent them to attack the "new" X-Men (Banshee, Nightcrawler, Storm, Wolverine) while they trained in the Danger Room under Cyclops (the sole remaining original X-Man at the time). These co