Metis is a major character in the story, Through the Looking Glass, which was created by Shirou Fujimura before being adopted by Demons Anarchy of Pride, prior to it's publishing. She is an Anti-Demon Suppression Unit designed by an unknown group tasked with eliminating Alice. For unknown reasons, she has instead chosen to serve beneath him. According to Rias, if his group were considered a peerage, she would be his Rook, alongside Flannel.