"Domain" is the term that has been adopted to describe the areas of influence created by Greater Demons, usually members of the Fiendish Court, within which the terrain and and even the laws of reality are shaped according to the master's essence. They are ruled over by a singular Demon "Lord", one who must be of considerable strength in order to exert their will so completely over their surrounds. Some Domains are dependent on their master's presence, travelling along with them and disappearing should their creator be slain; while others have been established so completely that they have become tied to the lands of Hellas themselves, becoming fixed in place and lingering on without their original creators, waiting for a new Lord to step in and claim the Domain as their own.
While only the most powerful of Demon's Domains exert influence over space and reality itself, all demons possess a domain in some form, most commonly expressing in an ability to draw a specific emotion from their victims or create temporary illusions of light and sound, though those are far from the only recorded manifestations.
Notable Domains include: