The evolution

Basically the world has evolved in such a way that humans are born with hidden powers from a different race and when they reach the age of 7 the go to somewhere only the gods know of (if u don't understand what I just said is idk where they go) to get thier powers and they change species (meaning if u have a goblin power you change into a goblin)but if you have animal powers you become a humanoid version of the animal