Ultimate X-Men Volume 6: Return Of The King

They've faced the weapon X program, Proteus and even the superhuman strikeforce known as the Ultimates. Now, still licking their wounds from their prior battles, can Professor Xavier's mutant team possibly survive the return of their most powerful foe? Starring all the X-Men you met in the movie - including Wolverine, Cyclops, Jean Grey and Storm.

Collecting Ultimate X-Men #26-33.