WARNING: The following contains spoilers for Way of X #1 by Si Spurrier, Bob Quinn, Java Tartaglia, VC's Clayton Cowles and Tom Muller, on sale now.
Krakoa is busier than ever. While the Hellfire Trading Company and its associates prepare for their upcoming Gala event and the first official team of X-Men in years gets ready to assemble, Nightcrawler has far more serious matters on his mind. After a mission infiltrating a mutant hate group's headquarters raised uncomfortable questions about Krakoa's ethics, Nightcrawler started questioning some of the most profound aspects of mutant life in Way of X #1.
To complicate matters further, he was just sent on a mission to find Legion, Professor X's Omega-level son who has an even deeper disdain for the direction Krakoa's leaders are heading.
During both the course of his most recent mission and his wanderings around Krakoa after returning, Nightcrawler has heard the same name come up again and again -- Patchwork Man. Professor X has a good idea of who this mythic figure is is, and he sends Nightcrawler to seek them out, noting that he is "one of the kind ones," and as such is uniquely suited for such a delicate encounter. When he finally comes across the Patchwork Man, who turns out to be Xavier's son, Legion. Nightcrawler finds him at the grave of the late precognitive mutant Blindfold. Nightcrawler does everything he can to reason and empathize with David, who proves to be sympathetic to Kurt for having been caught up in all of this. He even apologizes to Nightcrawler as the hero is dissolved into dust, but Legion is not willing to let his father inherit the world as he has Krakoa.
When he made his first appearance in 1985's New Mutants #26, by Chris Claremont and Bill Sienkiewicz, David Haller proved to be every bit as intimidating as he had been teased to be in the previous issue of the series. After growing up without Xavier, David's incredible psychic abilities manifested themselves when his mother and home were attacked by terrorists. The experience left him in a catatonic state, trapped within his own mind alongside the consciousness of the ringleader of the would-be assassins. This became something of a theme surrounding Legion, with him absorbing the minds of others while his own fractured into hundreds of unique personalities. Upon learning of David's existence, Xavier was more than willing to do everything in his power to help his son, frequently journeying into David's mindscape only to find near inconceivable horrors.
An Omega-Level mutant capable of spontaneously evolving new powers, David's mind creates a new personality to govern each of them, with the primary persona of Legion having the ability to warp both time and reality to his whims. These powers were used to go back in time and inadvertently cause the Age of Apocalypse by accidentally killing Charles Xavier instead of the intended target, Magneto. While this timeline was eventually averted, it was far from the only time that Legion's powers did far more harm than good. This, combined with his general instability even when in control of his powers has led to several confrontations with his father, and a deep divide between the two.
It makes perfect sense that Charles sent Nightcrawler to confront his son. That Legion retaliated against one of the "kind ones" the same way he would have if his father had shown up, as well as the fact that Legion seems to be totally aware of his own actions, only foretells bad things for the mutants of Krakoa's Quiet Council, if not the entirety of mutantkind. If David truly believes that his father has set Krakoa on course to become even more of a global superpower than it is, and in a way that is detrimental to the rest of the planet, there may not be any chance of stopping him. With any luck, Legion hasn't completely erased Nightcrawler from existence, and there is still some chance that he can get through to David before it's truly too late.