Soul

A Soul is a form of life energy native to most lifeforms in the Fogverse. Any lifeform that lives and breathes possesses one, all of which can be harnessed as an energy source of potentially unlimited power. In areas where the Fog has trapped the souls of the dead, creatures have been born that are capable of feeding on soul energy as sustenance, known as animavores. Getting eaten by an animavore means a "second death" for the ghosts of the dead.