She is the Seventh of the Eleven Fatui Harbingers and the leader of the Adventurers' Guild. She interprets all phenomena through the prism of mathematics, and is an elegant lady who is never absent from a tea party.

She was created by Alain Guillotin in the image of his deceased sister, Mary-Ann Guillotin, and kept Pulonia, his final creation, as her constant companion following Guillotin's death. Since the death of Pulonia, she is accompanied by a new robotic companion named Fagio.