Dark Soul

Souls are a type of entity that is linked to every living creature except for plants. Every creature that is alive has a soul, and this soul is a direct result of them being alive. They aren’t a tangible entity, but rather a metaphor for the brain. They represent the collection of a person's personality, interests, likes, dislikes, opinions, and generally everything about who they are. The reason why souls exist is the existence of magic essence; every living creature possesses a small amount of mana energy that is responsible for the soul’s existence.

The only context in which a soul would have a visual appearance, is when visiting someone else’s soul space or when the soul is being projected outside the body, the latter of which is even more rare than the former. The soul isn't a complete carbon copy of the person it belongs to both in appearance and in personality, it often look wildly different from the person and only possess part of their personality. They are always grey and depending on the type of soul it is, will have some features like a tail, a flame, and markings. A soul has no literal visual form and the only way to understand a being's inner working is through the metaphor expressed in five senses.

There are two types of souls; natural souls and developmental souls. A natural soul will have its nature be much more dominant and its nurture be less important but still influential over what the person is like; the other way round for a developmental soul. Nature can't do without nurture and nurture can't do without nature, so both aspects are present.

The soul space also holds an entity called the Person. This being is a metaphorical representation of the person the soul belongs to, identical in their current appearance and personality but with the added benefit of being aware that it's in the soul space and that the soul is right with them. The soul and the Person operate as one being, but are still capable of having discussions between each other. The result of these discussions ultimately decide how the real person will behave.

Very few people can look into the soul of another person, but if they were to do so, they would appear as a projection of their Person in an all grey endless room called the soul space where they can see and interact with the soul and the native Person. These interactions are not literal, but they do explain what is happening when two souls interact. Whenever a visiting Person is in this projected state, however, they cannot take the memories they acquire within the other person's soul space, as the memories would be stored in another person's temporary memory, not their own. When they leave, the memories the visiting Person acquired vanish, though the native soul and the native Person remember their interactions with the visiting Person.

To add onto that last point, few people know of the existence of their soul, at least in the way it appears. While the soul is capable of thought and even internal discussion of its own, these thoughts will not be transferred to the person's consciousness and only exist to benefit cognitive processes and subconscious thoughts through interaction with the Person. The soul and the Person decide what the person does through their combined thinking process. If the soul weren’t displayed as a metaphor, no one would be aware of its existence in a way some people are now.

Without a soul, a person would be alive but technically speaking braindead. Every cell in their body would still live given they get enough energy to keep working, but the driving force behind the brain would be gone. They say that the soul is located within the brain, the heart, and the mana pool,the last of which is located in the belly. Souls have the unique feature that their mana can empower other living beings, often gods, without making the person who owns it weaker. These two qualities are a reason why gods hunt souls when they can't get followers, and why Deimos only eats the brain, heart, and guts of his victims while leaving the rest untouched.