Xavier returns when Cyclops' and Havok's long-lost brother, Vulcan, is revived by the Collective energy released as a result of the "House of M" incident. Vulcan then attacks the X-Men. Xavier, now depowered but able to walk in the wake of "House of M", reveals that he had gathered and trained another team of X-Men (this one composed of students of Dr. Moira MacTaggert) sometime between the original team and the new X-Men team introduced in "Giant Size X-Men" #1. This team included Vulcan as a member. Like the "Giant Size" X-Men team, McTaggert's former students were sent to rescue the original X-Men from Krakoa, the living island. However, after rescuing Cyclops, McTaggert's former students were seemingly killed. Upon Cyclops' return, Xavier removed Cyclops' memories of the death of Vulcan and his teammates and began assembling the "Giant Size" X-Men. Vulcan skirmishes with the X-Men and eventually flees into space.