Cloyster @ Focus Sash
Jolly Nature 
Ability: Skill Link
EVs: 252 Atk / 252 Spe 
- Icicle Spear
- Shell Smash
- Ice Shard
Shell Smash once, spam Icicle Spear and claim ribbon. 
Icicle Spear/Shard are learned by Shellder as level up moves, don’t evolve until it has both. Shell Smash is a relearn move for Cloyster (or high level for Shellder).  Ice Shard is for Landorus in the rare event of it being faster (for example, you used a slow Cloyster with a different nature for some reason)