>>44946238Legendary Pokémon want to destroy humanity so the League aims to create a Champion that can capture these Legendaries and soothe them.
Said Champion is trained to be beyond the capabilities of a normal human and is trained to fight side by side with his perfect IV breeded Pokémon. He's equipped with a sword and gun that can have a Pokéball attached onto it, if a Pokémon is inside the ball and attached to sword or gun then they can transfer their moves into the weapons (E.g: Arcanine creates Fire sword and gun fires Fire Blast Bullets).
The story would have a focus on identity and free will. The Champion's power level grows with each mental conflict he settles. Such as whether he's okay with being the League's dog, should he kill the legendaries or try appeasing them, what will he do after his journey is over, is a fake life truly worth living, is a normal life even possible, are his Pokémon really his friends or just tools, and etc?
Picture is from Raidou Kuzunoha manga 