Shell Smash (Cloyster) @ White Herb / Focus Sash
Ability: Technician  
EVs: 252 Atk / 4 SpD / 252 Spe  
Adamant Nature  
- Shell Smash  
- Icicle Spear  
- Rock Blast  
- Ice Shard / Hydro Pump

Utility (Cloyster) @ Heavy-Duty Boots  
Ability: Regenerator  
EVs: 248 HP / 252 Def / 8 SpD  
Impish Nature  
- Spikes  
- Rapid Spin  
- Teleport  
- Icicle Spear