[5] After meeting with problems with racism and both encouragement from Daredevil and an encounter with the villain Pyro, Reyes reluctantly joined the X-Men.
Her first adventure involved saving Cyclops from a nanotech deep inside his body, which threatened to kill him, Reyes, other X-Men and obliterate anything in a three-mile radius.
It was while wearing Wasp's old uniform that Reyes became involved in a battle with the X-Men's frequent enemy, the N'Garai, interdimensional demons.
Reyes was trapped in the Neo's fortress below New York City and used a street drug called Rave to make her mutant powers more destructive, ensuring her survival.
[volume & issue needed] Reyes last appearance with the X-Men was at the time when Beast discovered the cure to the Legacy Virus.
[10] In X-Men: The 198 Files, it has been revealed that Cecilia's older non-mutant brother, Colonel Miguel Reyes, had been assigned to head O*N*E security on the Xavier School grounds, with the purpose of finding out the fate of his sister.
[volume & issue needed] After M-Day and her escape from Neverland, Cecilia volunteers at local homeless shelters as well as working out of her apartment.
When Magneto decides to bring back Shadowcat as a good will gesture, Cyclops asks specifically for her to help treat him of any injuries he might have suffered.
[13] After the events of Second Coming, Cecilia is partnered with Psylocke and sent to Mexico to locate the second of the Five Lights; the first mutants to manifest powers since M-Day.
Psylocke comes to the room and explains that something has happened, Gabriel's manifesting speed powers caused him to move so fast he is invisible to the naked eye.
Psylocke taps into Cecilia's powers to create a force field around his room so they would not lose him before Hope Summers could arrive to help.
They visit Cecilia at her apartment, and she agrees to give Gambit stitches, but is perturbed at being disturbed and admits she left Utopia to avoid such "stupidity".
[15] During the "Fear Itself" storyline, Cecilia is added to a team of X-Men opposing the "worthy" empowered Juggernaut in the form of Kuurth: Breaker of Stone.
Marc Buxton of Den of Geek said, "Dr. Cecilia Reyes has a really cool power, the ability to cast a force field that can protect herself or others, but the true specialness of the character is her desire to be a doctor instead of a superhero.
Reyes is the X-Men’s most skilled healer, a woman who seeks true service as a medical professional rather than an adventuring crusader.
Reyes is one of the most underutilized but humane of all the X-Men, a woman who has a clear sense of identity and purpose beyond throwing down with Unus, the Untouchable.
[25]: 219 In the Age of X-Man reality, Dr. Cecilia Reyes is the Medical Instructor of the 10th Year class within the Summers Institute Of Higher Learning, located in Winchester, NY.
[volume & issue needed] In X-Men: The End, she also had survived Neverland and has married Beast and they have three children (two boys and one girl), Ciaran, Francesca & Miguel McCoy.