This is a Pokemon concept.
This is set in the time where people have just started forming tribes with the creation and spread of the Pokeball. The idea is that this is a kingdom building fic where the main character is trying to become essentially the first champion (any region that you want to explore is fine).
The main character can be a reincarnator having foreknowledge of the Pokemon franchise, a transmigrator that has knowledge to start with the creation of the league, or a regular person growing in a tribe that has the ambition to become a leader and unite the tribes under one banner.
Take into account that the main character needs at least 4 close friends to cultivate into their elite 4, and to make note of at least 8 people that can be gym leader candidates. They can be tribe leaders, cultivated like the elite 4, or anyone that takes the main characters fancy. (Make note that anyone picked is assumed to become a master of a single type of pokemon, so you can expand on that type by making the main character help them even though it is assumed that the main character is a master of a single type as well)
I would really like to see it where the main character isn't a dragon master, but it is totally up to anyone that is willing to pick this up.