Yuri Alpha

The Vice-Captain, but de facto leader of the Pleiades. She is a Dullahan who uses a choker to keep her head attached to the rest of her body, causing her to appear to be human. She specializes in unarmed combat and uses Gauntlets in battle. She is programmed to behave like a teacher, because her creator was one, and the other Pleiades look up to her like a big sister. Like Sebas, she holds a primarily neutral stance towards outsiders, but unlike him, her sense of justice is not so strong that she'd help people like him.
(Source: Wikipedia)