Souls are the incorporeal and immortal essence of living beings. Mortals and all beings of good possess souls, while the forces of evil, such as demons and warlocks do not. However, half-breed evil beings, such as Cole Turner, are born with a soul due to their mortal side. When a soul dies, it can choose to reincarnate in another life or become a spirit.
Souls are valued as currency in the Underworld, as souls are obtained and traded in demonic auctions or traded for magical powers. In order to trade them, souls can be contained in glowing white orbs or balls of fire. Certain evil magical beings also feed on the souls of the living for sustenance or to increase one's power.