Quoted By:
Something like pic related.
He won't be the Champion, but he'll defeat the Elite Four right after you and you'll battle him for the title. Obviously you'll be healed up before the battle, and it will be almost impossible to lose - if you're down to your last Pokémon, it will either dodge all his attacks or survive them with 1HP, and will immediately cure itself of any status conditions. If you still manage to lose, the game will just pretend nothing happened and let you battle him again as if you never lost.
