Fia Gross

フィア・グロス, Exotic Onyx
The Exotic Onyx Kenrei no Shimamen Argos XIVs Otome. She doesnt trust the Aswad but she is very obedient to her master. She attacked Aswad and stole the technology that created Midoris REMs as well as give Rad and the others their cyborg bodies. Her Element is a halberd. From Wikipedia