After the teachers of the New Charles Xavier School left to attend the reading of Professor X's will, Celeste and her sisters set up a training session in the Danger Room for the others against holographic versions of the Avengers. She participated in the brawl until the program was shut down due to fellow teammate Triage's dislike of who they were fighting.
Celeste and the others came to Cyclops' aid after he was teleported from South Carolina back to the school by Malloy because of the failed attempt to contact him by Rachel Grey, which resulted in the destruction of a S.H.I.E.L.D. Helicarrier. Scott then had Magik teleport him back to the site as everyone looked on.
The Cuckoos then stood over the body of Magneto after he was transported to the school due to a confrontation between him, Cyclops and Matthew.
As Magneto want on saying that he failed Charles, Celeste and her sisters read the wayward thoughts of Tempus and her idea to travel back to the past to tell Xavier himself about how screwed up the future has become. They intervened especially Celeste and told her that is the worst idea of all bad ideas.
Later on she was in a telepathic hive mind with her sisters when they received a psionic blacklash after loosing their connection with Emma. As the other students asked what happened, Celeste and Phoebe told them that the new mutant killed Miss Frost.