System No. XX

System No. XX is the main antagonist in BlazBlue: Cross Tag Battle's Episode Mode.

Appearance
System No. XX started out as a voice without a physical form, but at the climax of the story, she attained one by establishing links through subjects she observed.

Bearing no humanoid features, System's appearance is that of a giant diamond wielding a levitating sword. Other smaller diamonds also float around her, and she has silver, metal plating with black engravings protecting her main diamond-shaped body. One of the engravings reads "No. XX." The color of each diamond changes depending on the route in story mode; in Episode BlazBlue, they are blue; in Episode P4A, they are yellow; in Episode Under Night In-Birth, they are purple; in Episode RWBY, they are red; and finally, in the Cooperation Ending, they are a combination of blue, yellow, purple, and red.