Kit was a street urchin who used to run with the gangs, living by her wits, her straight razor, and her knowledge of the streets. Free Running was her life, before it had a name: her world was the rooftops and the wall tops of the world, the back alleys and the fire escapes. Live fast, and never die, that was her motto, but it all changed after her encounter with the monster: a rogue Nephilim, who hunted down and killed the other members of her gang. Kit, with her knowledge of the streets, managed to escape, but not before the monster partially infected her with its curse.

She lived the next few years in the sewers, feeding on rats and offal, a monster hiding from the world, cursed with a skin that could endure any flame, and blood that ignited upon contact with air. It wasn't until she encountered a strange man named Adelard Clef that she learned to become human once again. Under the tutelage of that urban wizard, she eventually learned to control her monstrous side, and to live life as a (almost) normal girl once more.

Her powers are oriented towards speed and flame: in Nephilim form, her blood takes on properties similar to napalm of phosphorus, and ignites upon contact with air. Combined with skin that can endure temperatures of thousands of degrees Fahrenheit, she resembles little less than a living creature of flame, a bolt of fire in the night.