Lumbering but durable support vessels, arbiters are piloted by members of the Judicator Caste, and are infused with psionic energy. The Judicator uses the arbiter as a base to provide support using space-time manipulation. While capable of inflicting light damage. the arbiter is far more valued for its ability to create dynamic tactical advantages for the Great Fleet.

The Judicator can generate a large reality-warping field that serves to conceal nearby friendly units. The arbiter had to remain firmly anchored in space-time to generate the field and so is not concealed itself. Furthermore, arbiters can weaken space-time, tearing rifts in the fabric of space-time, creating a vortex linking another location to the arbiter's location. This can be used to move personnel and supplies over long distances. On the other hand, arbiters can also strengthen space-time and create discrete pockets of space-time, trapping objects and preventing those objects from interacting with objects outside of their pockets.