I decided to try and use Shuckle just for lolz, as battling was becoming boring seeing the same threats over and over again. I was surprised by the amounts of Rage quits and KO's I got from it (23 Rage quits so far).
Here is the Set I am using:
Shuckle (M) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 252 Def / 4 SDef
Careful Nature (+SDef, -SAtk)
- Power Share
- Rollout/Mud Slap
- Acupressure
- Rest
Baton pass it an Aqua Ring/Ingrain and this thing will not die. With Sand support it becomes ridiculously bulky on the Special side. The strategy is to come in on something that does pitiful damage to you (Everything) Power Share their counter so it does even less, then start Acupressure. It basically works like an Inconsistent Pokemon, albeit a bit harder to use. Rest up when necessary, 2 free turns for them doesn't hurt you since you take little damage anyway. Once you have everything at +6 begin to really reak havoc.
Rollout is the better in terms of overall attacking power, reaching isane levels after Power Share +6 and 5 turns. It also means that Fliers/Levitators don't wall you. And PP stalling is not and issue either. Mud Slap on the other hand means the enemy will be doing letterally nothing to you. +6 evasion and your defenses adding on the fact of decreased accuracy from mud slap is just mean. It is completely stopped by airborne Pokemon then though, and PP also becomes an issue, as even after Power Share and +6 it does pitiful damage.
Since you are running max Def, wouldn't it be better to run Impish?