Lumen

Another member of Midori's unit. Possesses a man's voice but a woman's body and speech pattern. He/She fights with a long metallic whip and can summon a fish-like "Slave" called Ketos. It is revealed that Lumen was killed during the assault on Cardair due to his/her body expiring. It is also hinted that Rad will also suffer this fate soon. In Yohko's picture it clearly depicts a young woman. It is unknown whether or not this is Lumen but it most likely is due to the height.

(Source: Wikipedia)