Celeste Gray took over control of her family with the betrayal of her mentor, Jaenelle Gray, whom she imprisoned in a hollow with the help of Alice Brown. She learned magic which allowed her to take over the body of a female blood relative when she died, granting her a form of immortality. Her family stole the knives that bound Elliott Brown to Alice and used them to commit terrible murders, tainting their power. They were eventually stolen back by Mordecai Brown, who hid them from both families. She greatly coveted the knives and started a campaign of terror against the motley when they fell into their possession. During the course of the conflict, she was killed by Jack O’ Dreams and moved into the body of Julia, who was then killed by Elliott. Her final host was Rebecca Gray, who fought the possession until Jaenelle was freed and trapped her in one of Jack’s soul jars, destroying her personality.
Celeste was utterly insane and a serial killer. She captured Alexandros, binding him in enchanted iron manacles, and tortured and killed teenager Claire, sending her head to Jack wrapped as a Christmas present.