X-Men: Everything You Need To Know Before Marvel's Big Relaunch
7. Age Of X-Man
For most of the recent Uncanny X-Men series, almost all of the titular team were trapped on another plane of existence created by X-Man (another child of Jean Grey and Scott Summers from an alternate future).
This left only Cyclops and a handful of X-Men to hold the line in their absence, meaning that mutants were very much on the backfoot - hence the subject of the next entry.
Anyway, the Age Of X-Man also provided another, far more intriguing, set-up involving Magneto. In order to destroy the fake utopia, Magneto was supposed to put the 'life seed' that X-Man had used to create his world into X-Man's chest.
Instead, Magneto left the 'seed' with X-Man, giving him a second chance to create a true utopia, along with what seemed to be part of Magneto himself. It's a rather ambiguous ending, but one that Hickman could use to great effect in his run.