How Spirits Work
There are many different types of spirits. It could even be said that everything alive is a spirit. Humanity exists as a result of a schism between spirits (See Origin of Humans).
The most powerful type of spirits are the Spirit Nobles. These are the spirits who control a domain. The power of the Spirit Nobles depend on the size of their domain. For example, the Spirit of Fire is inherently more powerful than the Spirit of Clouds that Look like Ducks.
Spirits reproduce sexually. The child of two spirits is always a spirit. The child of a spirit and a human is called a Danya.