The founder of the X-Men just made his big return to the Marvel Universe, but fans likely weren't expecting him to make his comeback this way.
SPOILERS for Astonishing X-Men #6 follow.
Professor X has been present in the new volume of Astonishing X-Men, written by Charles Soule, from the beginning. Apparently, sometime after being killed by Dark Phoenix Cyclops at the end of Avengers vs. X-Men, Xavier's psychic consciousness was found by his old enemy the Shadow King and imprisoned on the Astral Plane.
According to Astonishing X-Men #6, Xavier has been imprisoned like this for 100s of years (presumably time works differently on the Astral Plane), but he's found an unexpected escape. Xavier and the Shadow King have been playing a game using several of the X-Men as pawns. The Shadow King was about to use his captured pieces to make his grand escape into the material world when Professor X finally played his hand.
While the Shadow King had managed to possess both Gambit and Old Man Logan, Xavier had contacted the X-Men who were still present on the Astral Plane: Mystique, Rogue, and Fantomex. Together these mutants attacked the Shadow King, distracting him just enough that Xavier could break his psychic shackles.
Xavier managed to take out his enemy, but it didn't stop there. Apparently, he and Fantomex had come to some kind of an agreement. Without even realizing what was going on, Psylocke responded Fantomex's touch on her shoulder by turning around to see this:
That's right, Charles Xavier has apparently managed to possess the body of Fantomex. Now he's dropped the "Professor" title from his name and is simply going by "X."
There's something worrying about his turn of event, both because it seems out of character for the good professor and because his dialogue bubbles are using the same inverted white-on-black color scheme that the Shadow King used. Could he be infected by the Shadow King's influence?1comments
Solicitations for upcoming issues of Astonishing X-Men suggest that X is not the benevolent, peaceful leader that Professor X was, teasing that Xavier will try to save the world whether the world wants it not. It seems the X-Men's founder may have gone a little mad after spending centuries with the Shadow King.
Astonishing X-Men #6 is now on sale.