Celeste Marcella is your friendly neighborhood stray cat snack thief. Deimos Katsaros took her in from the streets, and they became friends, along with Tristan Trémaux. She is easy-going and even-tempered, not taking life too seriously. She likes to joke around, especially at the expense of Blair Donati and Ivy Huang-Ferraro, who drive her up a tree, and make her want to pick up and throw a tree at them with her super strength EP abilities.

Celeste is guarded about her emotions and her past until her world changes for the better when she meets Jaxon Tachibana. Celeste spent her life running from her feelings until she fell in love with him and had to face them. Celeste is a skilled and experienced fighter on the battlefield, but nothing could prepare her for the biggest fight of her life–love. She is affectionately referred to as his “Green Queen” by him, and she will fight tooth and nail to save him, as she often comes to his rescue when he’s in peril. Celeste fights with a cat-like finesse in her iconic catsuit, fitting to her attributes, such as her sharp fangs and cat-like mannerisms.

In her free time, she enjoys creating art. Despite not being particularly good at it, she proudly displays it and doesn’t take it to heart when it's shown at the Great Hall of Bad Art. Celeste is not easily offended and tends to think logically, rather than getting swept up in her emotions, but Blair and Ivy know what buttons to push to unravel her. But Jaxon always defends his Green Queen, as sometimes she needs saving, too.