Catherine (キャサリン Kyasarin ) is a member of the Blue Delmo with blonde wavy hair.
She is first seen after the parking lot altercation during Beautiful Agent, gathering up the Black Delmo and the Black Delmo Leader alongside other Blue Delmo. After this she is knocked out on a couple different occasions, once by Maypia Alexymetalia when she kicks an airshaft grid that ends up falling on her head, and the second time was after Rudolf Hagen instructed Catherine to escort Rion Aida to a cell. Upon entering said cell Rion somehow managed to surprise her and steal both her uniform and weapon, despite being handcuffed. She then leaves Catherine knocked out on the floor, half naked and with her feet and hands tied up. Despite having the upper hand, she was beaten easily by Rion because she was weak and useless, as well as overconfident. Rion knew the basics of combat, Catherine was no match for her. After the scene when Rion leaves her knocked out, she never reappears, it may be that she is one of the Delmo who perished aboard the ship.