She's a 200 years old gear and a morally-grey trickster with chaos magic abilities. Likes to troll people, be silly and drink strawberry milk. Acts out a demon persona for fun.
HERES SOME CONCEPT SKETCHES!!
She worked in a gear research lab in 2016, died by accident and was non-consensually injected with experimental gear cells, and turned into a gear. Her magical abilities were deemed to dangerous and unstable, which ended in the scientists locking her up in a dimensional prison, a form of magical stasis, where she was fully aware but without any mental stimuli for several years, driving her insane.
By sheer accident, she happened to have a copy of Ghoete's book "Faust, Part One" with her. Robbed of all other choices, she read the book (which she didn't enjoy at all) over and over again in her imprisonment until it was ingrained into her psyche. She started to identify with the devilish villain of the story Mephisto or Mephistopheles, who despises humans for thinking so highly of themselves while yet being just another animal. She starts to feel less and less human herself and blames them for treating her as lesser now just because of her being a gear now.
Once she finally breaks free, her mental state is so damaged that she massacres the lab staff in a frenzy. She frees the other test subjects, a herd of sheep turned into monstrous gears, who become her new family.
Her hatred for humanity gets kindled still by having to exist in a world that hates her for being what she was turned into. But over the almost 2 centuries of her life, it turns from a fiery lust for revenge into a jaded, mocking revulsion where she will turn everything into a joke, clown around and bully the humans who cross her path in a silly instead of harmful way.
She will reconsider her low opinion of humans when she meets a certain 9 feet doctor. Because I totally didn't only create her to ship her with Faust :)