The magic in The Sundered Lands works on a basis of rituals and sacrifice - in order to gain something, you must give something. Rituals take anywhere between hours and days to complete and the cost varies from tens of souls to hundreds or thousands - depending on the goal.
There are no mages, sorcerers or any kind of individual spellcasters - with the only exception being Vorathul Nox-Kael, who commands souls to cast spells and raise the dead as he pleases.