Cocytus is the Type Maiden with Advance Embryo of Hugo Lesseps. She was born out of Hugo's desire to know and punish the criminal who killed his father.Cocytus takes the form of a young girl entirely dressed in white, with a white dress and a white ushanka hat. She also has blue eyes. When transformed into her Advance form, she takes the form of a church-like ice armour that covers whatever vehicle Hugo is riding.Cocytus has a spunky personality, being unafraid to criticise her own Master or even the leader of their clan.