Partners in Noncrime
In this world, when a person dies, their soul usually separates from their body, which makes them a spirit and musn't be called human anymore. A certain kind of spirit has access to using one of the four elements, which are Earth, Fire, Air, and Water. But there are spirits who wants to rest in peace, making them uninvolved in any events related to the elements.
But where do spirits go? Alumoura, the alternate world of spirits. This world separates spirits into two, those who use elements, and those who chose the more peaceful path. But, it doesn't mean that these two kinds of spirits are on a war. They interact with other spirits, whether they use elements or not.
They lived a happy afterlife, even though evil spirits are there to create havoc, elemental spirits who are assigned to beat these evil spirits are present to vanquish evil.
But, little did they know, one evil spirit has started a plan to destroy Alumoura, slowly, but surely. This evil spirit's motives are unknown.