Almost all living things develop a soul, animal or otherwise. There's much debate on the religious implications, such as if there's something spiritual about the soul or if it's just as natural (albeit magical in nature) a part of a person as the consciousness. There's also debate on if animal's souls are as important as a race with Seynience. The common belief is that those without a conscience, or nonseynient animals, only have what are called protosouls, not developed enough to be called real souls. Some people claim that there's no such thing as protosouls, just souls, a belief strongly held by animal rights groups in particular. Souls are very hard to study so there remains many mysteries about them. Most of the things learned about souls is through observation of it's effects rather than being able to learn things through direct study.
What is known is that they are vital to magical powers. This can easily be seen in cloning, which is how a lot of what is known about souls was discovered. Despite having the same genes, even some that allows for genetic magic, the soul is the final piece of the puzzle to fully unlock this power, or any power at all for that matter. Because the soul cannot be copied outside of legendary magic, scientists were left baffled until they realized that the clones were developing normal souls without any powers, not allowing them to use their genetic magic. Only once someone was able to develop a legendary magic to copy the soul (by a small amount) of someone who could use that magic was this magic unlocked (by a similarly small amount).
Parts of a SoulEdit
Thought to be indestructible, this is the part of a soul that is least understood. It can also be classified as the "true soul" of a being from which other parts of the soul surround it.
Souls require a special energy to remain in our mortal plane called existence energy. A soul runs out of this energy as it exists, and once it runs out then the person dies from old age even if they were being kept healthy. People who are immortal can continually regenerate existence energy.
Energy surrounding the soul that isn't existence energy. It doesn't run out from simply existing and regenerates over time. It can be sent out of the body to use Magic or used inside of the body to act as aura/ki/etc.
Given off by souls of all types constantly like radiation.
Souls After DeathEdit
If the soul has existence energy or not is the primary factor of where it goes. If it has existence energy left from the person dying prematurely then the soul has a slight chance of remaining in the normal dimension as a ghost, as some people call it. Unless memories are so strong that they implant themselves on the soul, they don't have any memories of their life and instead act on instinct or familiar repetition. Some people can train to control their soul after death to get around this, but this takes complete devotion to master that often can only be found in wise gurus or the like. Once the soul runs out of existence energy then it travels in between dimensions, not able to exist in any of them by their own power.
Souls can potentially be interfered with by certain High Beings, especially if their soul had developed a strong affinity towards one. This allows them life after death, but seldom with any memories of their previous life, if the high being can create a body for their soul to occupy. It's also possible for a soul to be reincarnated by the soul spark finding it's way into a womb to become new life with a restored existence energy.