- Sanon - vessel
- Beatrice - master
- EVA-Beatrice - master
- Lord BATTLER - master
- Lady MARIA - master
- Ange Ushiromiya - friend
- ANGE-Beatrice- master
- Stakes of Purgatory - sisters
- Sakutarou - co-furniture / friend
She has short, curly, beige hair, fair skin and big red eyes. Her clothes are the same as those of the other Stakes. She wears the one-winged eagle on her "skirt".
Satan is an advanced-level Furniture created by Beatrice. She can act by her own will, but she cannot disobey the orders of her master. She is quite powerful while in her human form, but when she returns to her true form as Stake of Purgatory and fly at her enemy at high speed, she shows her full, terrifying potential.
Satan takes on the role of the quick fuse among the sisters. She is known for giving out rapid-fire scoldings, which makes the other sisters scared of her. Because of this, no one is willing to talk back to her, which means she is surprisingly lonely. She'll sometimes intentionally try to do things that should anger the other sisters in an attempt to gain attention, but they never scold her back, which leaves her even more lonely.