Beatrice  

Beako, Betty, ベアトリス

A sorceress was hired by Roswald to safeguard his extensive collection of ancient magic books in a grand library within the mansion. She possesses the power to transport any room inside the manor to this library at will, but is unable to fully escape its confines. Despite her aloof demeanor and harsh words towards Subaru, Beatrice cannot bear witnessing harm come to anyone and has become someone that Subaru can rely upon.