Elemental Spirit World's Mystery (4)

The Elemental Spirit Worlds are unique to only human worlds and every world is divided into Small, Normal and Greater Worlds depending on the energy absorbed by the World Core inside the Core Realm of any world.

As the grade of the world increases, the more powerful the specific world would become and more summoners would be born.

The higher the grade of the world, the more number of summoners would be born and thus, needed more number of Elemental Spirits to form contracts with.

Thus, a Smaller Human World only has 10 Elemental Spirits at one particular and since it was a Smaller Elemental Spirit World, it won't be that big for the summoner to search for the Elemental Spirits.