Nigredo is an NPC of the Great Tomb of Nazarick, she is the older sister of Albedo and Rubedo. Nigredo was imprisoned in the "Frozen Prison," situated on the 5th Floor of Nazarick and acted as an Area Guardian. She was released at the request of Yuri Alpha to help manage the new orphanage in E-Rantel. Nigredo has an appearance similar to Albedo's, in the sense of hair, but the similarity ends there as her face has no skin, but rather, a mass of exposed muscle. She has beautiful eyes and teeth, but there were no lips whatsoever, only beautiful pearly teeth. There are no eyelids, only brightly shining eyes. As such, her grotesque appearance horrified all the guild members of Ainz Ooal Gown, who all immediately attacked simultaneously upon seeing her. Though she acts insane and attacks her visitors without mercy if a baby-doll isn't given to her, Nigredo is assumed to be tender-hearted under normal conditions. She and Pestonya opposed killing innocent people kidnapped from the Re-Estize Kingdom. In addition, Nigredo had a soft spot for babies, perhaps even surpassing that of Pestonya’s. However, her compassion is limited to only that of infants. Once they live past the age of two, she sees them as nothing but sacks of meat to be disposed of.