Demon Prince is a collective term that applies to one of the nine powerful extraplanar beings who live outside Ather in what is known as The Beyond. While not considered as powerful as the Harkiron Gods, each is an extremely mighty entity in its own right. For reasons unknown, the Demon Princes cannot manifest themselves on Ather. Mortal practitioners may summon aspects of varying power of each Prince to barter for services or information, but it is considered a highly perilous endeavor, usually undertaken only by the most insane or desperate of casters.
Each Demon Prince can be summoned in five theoretical stages of increasing power: Aspect, Major Aspect, Greater Aspect, True Aspect, and Manifestation. The last stage is purely theoretical, involving summoning the entirety of the Prince to the Ather in a single location. Each aspect is in fact a portion of the Prince’s power, and actions taken by a particular aspect are known to all other aspects making up the collective consciousness of the Prince. In essence, every part of the Prince perceives and is aware of what every other part is doing at any given time, and remembers any past encounters with a subject that another of its aspects may have had.
When an aspect is summoned, it will generally first attempt to attack its summoner. If unable to do so, it will treat with its summoner. Different Demon Princes have different motives, with their immortal lifespan and alien perspective often making their requests seems strange. Their services are never without price though, usually in sacrifices, precious artifacts, or information.
Demons are vulnerable to silver, which is highly toxic to them. Silver can also be used as a focus when summoning them to grant the caster better control over what he conjures.