Lilian

Amane's twin sister who lost her body in her mother's womb. Due to her ISH ability, she exists as a spirit form, often residing in the body of a stuffed bear. Despite being one of the most powerful ISH users, she cannot use her abilities by herself as she lacks a proper body; however, she is able to lend her power to Amane and can unleash her full power if she fully merges with her.

(Source: Wikipedia)