『Beatrice』

A mysterious mage who was hired by Roswaal to keep his ancient magical tomes safe in his enormous library. She has the ability to warp any room in the mansion to this library whenever she chooses, but can't completely leave the mansion. Despite of her cold behavior and verbal abuses to Subaru, Beatrice can't stand if people are hurt in front of her and becomes one of people that Subaru can trust.