Go with Froslass as its fast and can hit fairly hard. In the elite 4, froslass will be able to take out a few of the bug pokemon, a few of the ground pokemon and the majority of the psychic pokemon. Also, froslass will be good against some of the champion's pokemon. Also, Froslass is an evolved pokemon so its going to be better than a mantyke with is a pre-evo. Good luck in the elite 4!! When you have evolved the last of you pokemon, we have to battle.