Complex sentence: Cyclops doesn't believe him and can't fathom why the Professor would make him forget his third brother, whilst over his shoulder the shadowy figure reveals himself-as Professor X who it seems has regained use of his legs after the events of House of M !
Split into simpler sentences: Cyclops doesn't believe him and can't fathom why the Professor would make him forget his third brother, whilst over his shoulder, the shadowy figure reveals himself. It is Professor Charles Xavier, who it seems has regained use of his legs after the events of House of M!