Pokémon FireRed and LeafGreen/Pokémon League Rematch
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Well, you've done everything you could on the Sevii Islands, so you decide to take one the Elite Four again. Well, If you haven't already, make sure your Pokemon are level 65+ unless you're feeling very confident. Why? Well, unless you want your butt kicked, I sugest you do it. All of the Elite Four members have leveled all of their Pokemon by 10, so you should too.