Reincarnated in Pokemon

A person is killed by the infamous truck-kun and reincarnated in Pokemon but that Pokemon world is not what the Pokemon world he recognize, Pokemon are ruthless and savage, humans become a cage bird hiding inside the walls, scared of Pokemon.

Since all the people are scared of pokemon, the league start a selection program every year. The league will select 20 kids to become a trainer and protect the city. Since the people are scared they didn't even think about it's for the existence of humanity.

Outside the walls nest of different kind of pokemon from different generations, the league implement a trial that the 20 kids that get picked to become a trainer will be thrown in the field to catch their own Pokemon to prove that the trainer had strength to become a trainer, but Pokemon are ruthless out of 20 most of the survivors are around 5, so what will the mc do?

Well not a problem there's a system for that.