Aeons

Aeons are creatures who live in an alternate dimension who are able to enter this one by creating bodies made from magical energy.  In order to do so they must form a contract with a being in this plane who will gather the necessary energy to summon them, after which they will typically perform tasks for their summoner.
Because of the requirements to summon them, the only people with whom they have interaction are mages or other beings skilled in the use of Magic.
==Physiology==
It is unknown exactly what state they exist in on their native plane, but when brought to this one they possess bodies composed of magical energy and are able to sustain themselves for as long as the energy used to summon them lasts.  In this way the makeup of their bodies is largely the same, though the outside features are often wildly different.  Some are humanoid in form, while others resemble massive beasts.
==Powers==
Aeons possess powers which bridge every magical sphere and thanks to their long lives are extremely accomplished in wielding them.  While in their home plane they are able to use their powers normally, when brought to this plane they are able to draw only on the energy available from their summoning.  Use of their powers or taking damage drains them of magic, but an aeon which is not using its powers or exerting itself can sustain their material body for unusually long times.  Because they can be summoned for very little magic, low level aeons are able to be summoned for much longer periods.  As an aeon gets higher and higher in level though, it takes more magic to be able to summon them.  Aeons at the Legendary level can only generally be called to perform one attack (or other task) before their body dissipates.  When an Aeon runs out of magical energy the body made for them will disappear and they will return to their own dimension.
==Personality==
Aeons have a wide range of personalities largely colored by the sphere they belong to and whether they belong to the Black or White Kingdoms.
==Culture and Society==
It has been suggested that Aeon society in their native plane is divided into kingdoms of light and dark mirroring black and white magic.  It appears to be highly stratified, with ascending classes of Aeons from “young” aeons which can be summoned by anyone to ones of advanced age and power who will only serve the strongest of Mages.  Each Kingdom is ruled by a King who is obeyed without question by lesser Aeons.
==Religion==
Aeons believe themselves to be deities and therefore do not really have religion per se.