The weakest of the inevitables so far described, arbiters are Tiny factotums for the forces of Law.
A Lawful holy site has called a manticore to be its guardian, augmenting it with permanent fox’s cunning and owl’s wisdom effects. The formerly rapacious (and, it must be said, happily so) Razormane is now tormented by his newly boosted consciousness…and by his would-be consciences: two bickering arbiters manifested to aid and educate him.
Appalled at watching his baron descend into abject (but strictly legal) cruelty, a Lawful Neutral court wizard finally throws in with the budding rebellion. His arbiter familiar, Nul-Quorum-One, is doing everything it can to cajole its master into returning to their rightful liege lord’s service—including hiring adventurers to bring him back by force.
An extraordinarily large flock of arbiters has overrun the town of Brighton, inscribing it with strange symbols and commanding obedience. Despite their truespeech ability, they insist on communicating primarily in Celestial, and have even employed their electric bursts on a councilman whose questioning of them turned violent.
—Pathfinder Bestiary 2 162