Tachibana Kukuri Fanclub

A strange girl in from their school that looks like Kakeru's dead sister. She is one year older than Yuka and Kakeru. She has the ability to material her soul into the form of an angel that appeared chained. She calls the angel "Abraxas". "Abraxas" attacks by sending out chains with sharp blades. She is the adopted daughter of the famous novelist in the area whom she inherited her last name. She has no memories before the age of 13 seems to have lost her voice. She uses a sketchbook for communication. In one scene of 11eyes CrossOver, it is noted by Shuu indirectly that her power is very unique and incredibly difficult to reproduce by sorcerers.
Taken from Wiki