Xavier's evil twin Cassandra Nova, whom Xavier attempted to kill while they were both in their mother's womb, orders a group of rogue Sentinels to destroy the independent mutant nation of Genosha. Magneto, who is Genosha's leader, appears to die along with the vast majority of the nation's inhabitants. Nova then takes over Xavier's body. Posing as Xavier, she reveals his mutation to the world, something he needed to do but did not want to sully his reputation over, before going into space and crippling the Shi'ar Empire. The X-Men restore Xavier, but Lilandra, believing that too much disaster has come from the Shi'ar's involvement with the X-Men, annuls her marriage to Xavier. Lilandra previously had gone insane and tried to assassinate Charles on a trip to Mumbai. During this period, a mutant named Xorn joins the X-Men. Xorn uses his healing power to restore Xavier's use of his legs.