Souls are a species that travels from planet to planet. On the planet they are on, the most common inhabitant is the one that they take over. They are implanted within the body through a slice at the back of the neck. A healer will cut the host body open on the back of the neck and slide the soul into place where it attaches to the host body and takes it over. Once a host takes over a body it takes it over completely, mind and all. The mind of the actual host is lost and only the soul’s mind is present within the body.

The first dead give-away of if a body is a host or a human is the eyes. If a light is shone into the eyes of a host there is a silver ring present that looks like a reflector within their eyes. Humans do not have this so its very easy to tell them apart. All hosts have a straight line scar on the back of their neck where they were implanted into the host body.

A resisting host is a body where the original mind will not give up its grasp on its body. So not only with the soul’s mind be within the body but so will the mind of the human. They are both trapped within the same body, which makes it very difficult on both parties. The Host can also try and keep memories to themselves instead of giving them to the soul. Some Hosts can even take their body back if the soul isn't strong enough.