Spirits are sentient beings of energy. Each have their own origin on how they came to be. There are many different types of spirits, though most fall into the four areas of power that the four people are bonded to; earth, atmosphere, animal, and light. Though there are closer associations between spirits of a particular area and the corresponding people, such as earth spirits and ameshas, spirits rarely deal exclusively with anyone. Spirits have extremely fluid forms that can frequently change. Because they are not completely within the physical world, they generally cannot directly affect or be affected by it, unless it is by magic that was specifically learned to interact with them.