Like energy, every living being possesses a soul. The soul is a glowing orb that lies in the chest, opposite the side of the heart. The soul is the furnace that powers the body, as well as the owner's subconscious. Without a soul, a body is either catatonic or dead.
The soul may exist outside the body, which is expanded on when discussing ghosts. If one's soul remains intact and returns to a functioning body, then all is well. A soul that leaves a body for protracted periods might return to a dead body, since bodies atrophy over time without a soul.
Souls can be damaged, but not destroyed. Damage is caused only by offensive energy, including items physically manifested with energy. Some anomalies have the ability to knock a soul out of a body.
The soul can mutate, which introduces a new issue—demons, a growth attached to the soul like a parasite. The color of the soul is personal to its owner. Soul colors can change over time; a rare phenomenon no one can explain. For anomalies, the color of the soul shows up in their energy when they use their abilities and utilize spells. In corporeal anomalies, a ring of light the color of their soul surrounds their pupil. This color expands out into the iris when using moderate energy, and can even envelop the whole eye in a glow with heavy energy usage.