Soul

A part of living things have a soul. A soul is a producer of Life energy. Living things that consume above a certain amount of life energy have a soul because, Life energy radiation isn't enough to sustain them. Plants, bacteria and small immobile species don't have souls typicly while other life tipicly does and often can't even live without one.

Energy recharging of the soul

The soul doesn’t always produce energy. One of the functions of sleep seems to be to regenerate magical energy. Some people can train themselves to also have their soul produce life energy during meditation, an example is Monks who can regain magical energy on an hour of meditation.

A soul’s impact

Inanimate objects don’t have a soul in a normal situation, they simply have life energy and crumble without it. Things that live, consume life energy over time and need to refill that energy somehow to keep living(it doesn’t replace food but rather is another source like you need to both eat and drink.) Things that don’t consume a lot of life energy can be alive without a soul.

A soul’s journey

When a soul dies it changes. a soul kind of goes back to a base state it takes the life it lived from the body and mind it was connected to and the information on itself and stores it away so that it can be reached if needed. The memories, and changes to the soul are remembered. When that soul goes to an afterlife it unlocks the information (of all lives) again so that it can exist in the afterlife. When a person is reincarnated into a new body their previous lives are stored not gone but not accessible. There are exceptions, if a previous life had tremendous Magic, that can bleed out and affect this life too and if you come into contact with things from previous lives the memories of that life can become unlocked. If you are resurrected into a body that your soul recognizes they allow that

rules of reincarnation

There seems to be a logic behind how reincarnation works. While it isn’t completely known, reincarnation doesn’t seem to be completely random. It seems creatures reincarnate based on factors of their previous life, a creature is relatively often the same species group as it was before. However sometimes gods or other powerful entities force souls to a body on reincarnation and in that scenario it of course ignores those rules

Soul type

There are multiple types of souls. Different types of souls are from different sources, for example all tree souls are from the World tree. Different souls can’t create offspring together. It is possible but hard to transmute your soul type. When you transmute your soul you change in physicality to account for the new soul. Changes make you appear like a creature from that universe, this often comes with some abilities as well.When a person takes in multiple souls of different types it will cause them great pain and they won’t be able to harness all the souls so there is no benefit to it, all it can cause is split personality if both souls have a personality.
Souls with their type can also be more or less powerfull, souls that have powerfull magics in them like souls that belonged to a god for example will often have innate magics attached to it.

Manifestation

The soul is invisible under most sircumstances. when people do see them they are glowing balls where size size and color indicate information about the soul.