Heroic Summoning was an Astral power through which a spirit could be recalled from the Astral Sea and anchored in a projected body. Its name refers to the spirits most commonly summoned: those of past heroes, who due to their typically strong wills were easier to recall from the 'collective consciousness.'
The summoning required a complex ritual, beginning with the preparation of a magic circle which served several functions. It first aided with the otherwise prohibitively exhausting Projection process and sustain the projected body, and to further ease the burden, the user would project only a vaguely-defined body at first. The user would then open their mind to the Astral Sea, locate the desired spirit, and, often forcibly, pull the spirit into the physical dimension, whereupon the magic circle would serve the additional function of drawing the spirit into the projected body, which would then take the form of the summoned individual. Finally, the circle would temporarily bind the summoned individual to prevent them from interrupting the final step of the ritual, wherein the user placed a "Command Spell", which linked the summoner and the summoned spirit, allowing the summoner to provide Astral Energy to sustain the spirit, and effected a powerful form of mind-manipulation which would force the summoned individual to obey the summoner.
Heroic Summoning could normally be used only by talented Astral Users, however, there were ways to simplify the process. Any link between the summoner and the summoned, such as if the summoner was related to the desired spirit, or in possession of something belonging to the desired spirit, could ease the process of locating the spirit. If the spirit willingly allowed itself to be summoned, both the summoning and application of the Command Spell would be significantly easier.