Deirdre Archleone

Deirdre was a member of the Order of the Blackened Denarius and the host of an unknown fallen angel. She first appeared in Death Masks.

Description
She was the daughter of Nicodemus Archleone and Polonius Lartessa.

Deirdre had a lean face, long dark hair, and dark eyes that "showed a full measure of both Nicodemus’s soulless calculation and Tessa’s heartless selfishness."

Deirdre's demonic form was described has having legs that were oddly hinged and reverse-jointed, with panther's claws. She had skin of metallic green scales (although she is described as having bright red skin in Small Favor, and later violet, not to be confused with Rosanna, who is red), and her arms ended in four-fingered, metallic-clawed hands. She had two sets of eyes, one luminescent green, one glowing cherry red, and a luminous sigil burned at the centre of her forehead. Her hair was between ten and fifteen feet long and seemingly looked like it had been cut in one-inch strips from half a mile of sheet metal; it had the ability of supporting her weight like a dozen additional limbs, and could be thrown at people.

She was nicknamed Madame Medusa and Joan Jet Hair, spoke with an "odd, vaguely British accent", and was devoted enough to her father to allow him to sacrifice her life for his causes.

Skin Game
In Skin Game, Deirdre is sacrificed by her father to unlock the Gate of Blood. Her soul was bound to the Underworld, and while Harry initially expressed irritation that she would therefore escape eternal punishment for her numerous crimes, Hades angrily reminded Harry that an eternity in his domain was hardly an improvement.