Book of the Sky

in a world with magical abilities is mainstream, it is dangerous enough that the deities watching over must step in to protect it. These gods are referred to as Numinisian gods, and they are all the children of the mother goddess, Numinis. 

To keep the world safe, some of the gods imbued certain souls with fractions of their power. These souls are constantly immediately into different lives each time the body dies. The souls are referred to as Vessels, and they are destined to be the strongest the world has to offer. 

Not everyone who aims for such strength is one of these Vessels, though.