Fia Gross

'The Exotic Onyx' (塊麗の縞瑪瑙 Kenrei no Shimamenō), Argos XIV's Otome. She doesn't trust the Aswad, but she is very obedient to her master. She attacked Aswad and stole the technology that created Midori's REMs as well as give Rad and the others their cyborg bodies. Her Element is a halberd.
-From Wikipedia