Nihilego @ Choice Scarf 
Ability: Beast Boost 
EVs: 252 SpA / 4 SpD / 252 Spe 
Timid Nature 
IVs: 0 Atk 
- Power Gem / Meteor Shower 
- Toxic Spikes / Stealth Rock / Psychic
- Hidden Power [Ice] 
- Acid Melt

Other Options: Distress Glass or Choice Specs, Grass Knot, Thunderbolt, Dimension Warp (ability), Acid Spray, Hidden Power [Fire]