History
Magneto declared war on all of humanity after years of watching Mutants get killed and was joined by Charles Xavier. They were initially winning the war, until S.H.I.E.L.D. kidnapped Reed Richards' family and used him to create a virus that wiped out the whole of mutantkind, killing Magneto and Charles. Reed was devastated by the genocide he had caused, so he traveled to Mars with the Fantastic Four and four mutant test-tube babies and raised the children to adolescence. He formed the New Mutants but was constantly worried about his charges finding out the truth of his involvement in the genocide.[1]