Magneto was going to set the games in motion with a dark and delicately done present for Charles. He needed to give him a proper welcome home. They were old 'friends' of sorts. Heading in with several of his orginal Brotherhood members and destroying the place. Using his powers over metal based materials he forced Cerebro and the surrounding machines to all but essentially implode upon themselves. He knew his friend would be home within the day period. Setting off a bomb mystique had smooth talked from a military officer days prior in one of her many disguises. The detonation blast would only cover the extent of the area yet would shake the foundations of the school. No more force than a small scale earthquake. Then like shadows of the night come dawn, he and his mutants were gone. Leaving nothing but a black singed smear, sparking wires and a completely destroyed cerebro machine behind.