The term essence refers to the magical force that flows through most everything in Kulthea, owing to the strong connection to the Essence Worlds. This force acts with potentially intelligent action. Which is what makes many magical effect possible. Indeed, for an intelligent being, it's essence is an important part of its being.

Wizardry is generally the art of manipulating the essence. For some few who either worship a monotheistic diety associated with the essence (for instance Zanar), upon death their essence will lead their spark to an afterlife in one of the Essence Worlds that's associated with their worship.