What If? Astonishing X-Men #1

The X-Men discover that Ord has resurrected Jean rather than Colossus but her reunion with the team does not go smoothly. Angry at Jean's return, Emma falls under the influence of Cassandra Nova who has the Cuckoo Sisters release the Phoenix force trapped inside of them into her. Now with the power of the Phoenix, Emma kills Ord and flies to his planet, destroying that as well. Emma returns to Earth to battle her former friends and it is Kitty who is able to bring her down. As the Phoenix Force is violently expelled from Emma's body, Kitty is caught in the blast and killed.