The miniseries X-Men: The End (written by Chris Claremont) details the last adventures of the X-Men in a possible future. In this reality, Rachel played a central role, and was the political campaign manager of Kitty Pryde (Chicago mayoral candidate). However, she abandoned this position after Cassandra Nova led a series of attacks on the X-Men and their allies. She traveled alongside Cable into Shi'ar space. After a Professor X was taken hostage by Nova, and she entered his psyche in order to free him. However, Nova traps her and Lilandra within. She seemingly kills them both, but Rachel used the power of the Phoenix to save herself, and incapacitates Nova. They leave Xavier's mind, and continue the battle in Rachel's mind, where Rachel is overpowered. Cassandra, using Rachel's body, kills Jean Grey and Cyclops, leaving Rachel forced to watch the ordeal. Nova then leaves Rachel's body, stealing the Phoenix force. The Phoenix being the only thing keeping her alive after her Cassandra destroyed her mental form, she simply died.
Read more about this topic: Rachel Summers, Other Versions