Exa is a plane that exists beyond the normal world of Fels. It can only be reached by those adept with odylicism, through some kind of agency (portal, periapt and the like) or by the ability of supernals themselves. Exa is infinite and mostly uncharted. Its primordial state is a vault of deep cerulean blue that extends to infinity in all directions (and some folk refer to it as the Blue) but this can be changed to suit the whim or intent of the power or sorcerer that makes their home there. Realms made by sorcerers and others within are known as Abodes, the most famous of which is Nhaliscalane where Aegyptus Juvens dwelt for a time.
Due to its innate odylic nature, those with no magical ability cannot remain in Exa for long and are usually expelled in a few hours. Logically, items can be worn to obviate this and there are other characteristics whereby one can remain for an extended period or indefinitely.