While Shuckle has the Defenses to wall like noone else, he has a BIG problem, his HP. Base 20 HP is terrible. He is like a wall of diamond as thick as a human hair. Mew, on the other hand, has base 100 HP, which when combined with Shuckle's base 230 defenses , is flippin' awesome.
Since Shuckle's offenses suck, He is better used for stalling.
Mew @ Leftovers
EVs: 252 HP / 100 Def / 156 SDef
Bold Nature (+Def, -Atk)
- Thunder Wave
- Psychic (For taunt)
Turtle Sexy (Shuckle) (F) @ Leftovers
EVs: 4 Atk / 252 Def / 252 SDef
Impish Nature (+Def, -SAtk)
- Toxic (Stall Out)
- Rest (Heal)
- Power Split/ Protect(cripple sweepers or protect for +1 Lefties)
- Earthquake (Taunt and to hit Steel and Poison types that toxic does not work on.)