Fans of Jonathan Hickman's ongoing tenure as Marvel's "Head of X" know all about the X-Men's new island paradise, Krakoa. On the mutant island which shelters and feeds them, the X-Men have finally had time to marshal their resources and find a unique combination of mutant powers which, when used in conjunction, can bring any Krakoan citizen back to life when they fall. The thing is, one of the very first X-Men could do the same thing all on their own.
What some readers may not know is that an original X-Men member - one who was present in the first published comic encounter with Krakoa - boasted healing and resurrection abilities long before Krakoa became an ally of mutantkind. So, who was the original X-Men member who offered mutant resurrection before it became Krakoan policy, and where are they now?
Who is more fitting as the wielder of resurrection powers than the winged hero known as Angel? Warren Worthington III possesses a rich comic history, perhaps even more complex than Krakoa's. A series of changing wings, abilities, and mental states have all shaped Angel's stories, but before Krakoa was ever the X-Men's Garden of Eden, Angel could have been their messiah... if they'd been paying attention.
Angel has been the subject of many changes over Marvel history, and Apocalypse's toying with his DNA left him with a whole new Archangel form, but Warren's healing powers were apparently natural - the result of a secondary mutation explored in Chuck Austen's generally deplored run on Uncanny X-Men, which suggested Warren's new powers were thanks to the special qualities of his blood. Austen also introduced the idea that Marvel's mutants are immune to AIDs - a detail future writers haven't been particularly eager to expand upon.
This power set re-emerged after X-Force's "Dark Angel Saga," in which the use of Celestial technology saved Warren's life (and burned away his Archangel abilities and form) at the cost of wiping his mind, leaving him with a new, almost childlike mentality. After this, Angel is able to bring back the deceased thanks to new powers inherited from the Celestial Life Seed - beginning with a dead dog in Wolverine and the X-Men #4 - but his new powers cause him to believe he's a literal angel. This fact is distressing for all the X-Men, especially since Warren's work with X-Force isn't widely known, but is particularly upsetting to a time-displaced Warren Worthington III, a younger version of Angel brought forward in time and left utterly shaken by a future in which his mind is wiped, he believes he's an angel, and none of his friends seem to be interested in finding out how it happened.
Angel's healing abilities have varied since, with few writers choosing to explore the extent of his powers and opting instead to resurrect his Archangel persona and tell stories of Warren dealing death rather than preventing it. Despite this, the Celestials are some of the most powerful beings in Marvel canon, and it's reasonable to expect that Warren had enough juice to be a major resource to his team, up to and including resurrecting them from death. Perhaps future writers will return to Angel's more existentially terrifying abilities, or maybe this is another chapter in the story of the founding X-Man who's just never going to get the credit he's owed.