Power Swap Shuckle
Because I read the forum rules, I won't try to dissuade you from using Shuckle.
One day, for the heck of it, I decided to try to breed the best Shuckle I could possibly come up with, given the new TMs and Egg moves he can learn.
Shuckle @ Life Orb
Relaxed
EV: 252 def, 252 spdef, 6 hp
Power Trick
Stone Edge / Return ( w/ 255 friendship )
Earthquake
Encore/Attract/Swagger
The 4th move is something to potentially keep you alive a bit longer if things go awry.
But you need a way to get him into battle, then use Power Trick, have him survive, then be fast enough to actually sweep.
The only decent answer I could find is by using one of my favorite Pokemon:
Smeargle (Jolly) @ Focus Sash
Own Tempo
EVs: 252 speed; 129 def; 129 spdef
Spore
Substitute
Trick Room
Baton Pass
Lead with Smeargle. In a perfect world, it typically plays out like this:
1. Spore ( opponent falls asleep )
2. Substitute
3. Trick Room ( or Spore again if opponent wakes or switches ) ( 1st turn of Trick Room)
4. Baton Pass in Shuckle ( 2nd turn of Trick Room)
5. Power Trick w/ Shuckle ( 3rd turn of Trick Room )
At this point your opponent could either be sleeping ( awesome ), or has just woken up, thus your substitute should save you if you are facing a physical sweeper. If you are facing a special sweeper, then meh, who cares, you have absurd sp def.
6. sweep ( 4th turn of Trick Room )
7. sweep ( 5th turn of Trick Room )
8. sweep
A couple of things to note:
This set up is mainly for the battle tower, as you only have 2 turns of sweeping before the trick room ends. After that you can be in real trouble with the speed of a snail :\
The chain is hard to pull off, a number of things can go wrong, so you really have to be adept at judging how the computer will react to all of this and mix things up accordingly.
It is a fun challenge though.