Name: Isolde (Or Lilith, or Rosalie. She has many names.)
Canon: Original Character
Age: 477 years old, but always looks anywhere from late teens to a very, very, very well kept for mid to late forties.
Height: Varies, but she often likes being supermodel tall. So anywhere from 5'8 (172 cm) to six feet tall. (182 cm)
Weight: Varies, but you'll never know.
Build: Varies, but like a tall, sleek but still curvy appearance. Think Victoria Secret model that decided to get some surgery on her tits and ass.
Appearance: She's an outright shapeshifter, but often appears as a drop-dead gorgeous woman that acts like she clearly knows it. Her hair changes on mood, the body changes on a whim, even her race can be changed if she feels like it. She does have a favored look however, it's a tall, pale-skinned, long-haired redhead with grey-blue eyes and freckles. This appearance tends to wear glasses.

History: A Scottish witch born sometime in the late 16th century, she began dabbling in various folk magic with other women in her village around her twenties and later went into darker magics later out of a great need. (She refuses to tell what exactly.) She, along with other women of her village was tried and killed for their involvement in witchcraft. She spent at least a hundred years in hell before she got the opportunity to leave as deal-maker. Eventually, she left Scotland for the US and has been staying there since in various forms and names.

Her relationship with Hell is rather in a bad shape right now, as she refuses to make deals based in the various covens and communities she sets herself in. (As well as a few other things that can't be forgiven. Stealing beasts for her own personal use, killing the various higher ranking demons they send after her, etc...)
Despite this, her relationship with humans (and humanity) is regulated as either a thing that keeps her amused or a horrible race that deserves every indignity done to them. She has killed and disrupted many human lives and will mostly continue doing it.

Personality: To put in the simplest terms possible, Isolde is kinda a bitch. She's often rude, vain as all hell, contrary, and often insulting and/or teasing to people. (Especially human men.) Being a demon, she often likes causing chaos for the sake of it and doesn't seem to care about her what her actions do. (After all, consequences are for mortals and lesser Demons that can't crawl out the pit and 'die' on the surface.)

Despite all this (and what she tells people) there is a bit more to than that. Once upon a time she wasn't so callous and worn from all the time, the magic and all the wear and tear living for much, much longer than any human has any business living. And frankly, she sort of has a death wish... don't expect her to ever admit that to anyone, let alone a human. They are just meals, pretty little toys to play with after all.