The book series, malazan book of the fallen, which I spelled wrong. In a gross oversimplification, there's pocket dimensions called Warrens, from which mages draw from, Warrens are psedo-elemental, with things like "The Sky" and "Fire" but also things like "Death" and "Mind". Non-human Races also have their own (Elder Warrens), so like the Moon elves would have their own Moon-Warren, the Sirens would have a Song-Warren, and so on.