Pokemon to bring to Purity Forest in order in bestness and skills:
1) Charizard!!! Has Heat Wave and other strong moves to fend off those nasty skarmorys and grass types. Also levels up considerably speedy, and HP goes well.
2) Venusaur! With him, i got to floor 64! His best weapon is Sleep Powder for those hard-hitters to make an easy get away! Also, Razor Leaf seems to prove efficiently effective to most any type!
And as for Mew, well, she sucks! I'm doing purity forest with her right now and she just plain sucks in moves, stats and HP!
She doesn't level up very fast much either! She's not what she's said all up-to-be you know! She does level up fast, but in terms overall, she IS NOT Suitable for Purity Forest!!!
http://i258.photobucket.com/albums/hh278/xpokemon_rocksx/lekngklrengre.png