Fall Of X has played off X-Men history in a lot of ways. This has been a hallmark of the Krakoa Era in general; nearly every title launched during the last five years has paid homage to the X-Men's past in this glorious new future. Fall Of X itself is heavily indebted to several '80s X-Men stories, from "Mutant Massacre" to Fall Of The Mutants to Days Of Future Past, and many of that decade's greatest X-Men have played a big role in the stories that drive Fall Of X. However, one major character is missing
Source：https://www.cbr.com/phoenix-rachel-summers-xmen-fall-of-x-marvel/
