Zero 9

Zero 9 official names were Sonya and Invincible. Her core contains the remains of "Invincible" Linda, which are the dominant personality in the body. She uses twin sabers instead of the typical claymore to fight. Her awakened form is a large, circular, silvery being with exceptionally hard skin and 4 arms. In each arm, she uses a saber to quickly hack enemies apart.

Sonya - invincible isn't very bright and looks down on others, yet appears to be one of the older zeros (at most 300 years old). She sees her enemies as weak and is quick to use her full power.

She fought against Arwen, quickly reverting to her awakened form, crippling Arwen. However, she retreated and let Roze finish her on Roze's request. She later challenged Noble to a fight, thrilled to fight an abyssal one. Zero 7 tried to rescue her but they both were hit with a powerful attack which completely destroyed their bodies, leaving only their cores.