Beatrice

Beatrice is a member of the Emilia Camp and the former caretaker of the Forbidden Library in Roswaal's old manor. Despite her childlike appearance, she is an artificial spirit created some four centuries ago by the Witch of Greed, Echidna.

She looks like a lovely girl of eleven or twelve, with sky-blue, butterfly-patterned eyes and long cream-blonde hair worn in drill-shaped twin tails. Haughty and proud of her mastery of Yin magic, she refers to herself as "Betty", ends her sentences with quirks like "I suppose", and hides a soft, lonely heart behind her tsundere bravado.

Echidna left Beatrice to guard the library and to wait for "That Person" who would give her purpose. After centuries of doubt, she shut herself away from the world and from each generation of House Mathers — until her meeting with Subaru at the manor gradually begins to change her fate.