Nihilego @ Choice Specs  
Ability: Beast Boost  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Power Gem  
- Sludge Wave  
- Dazzling Gleam  
- Grass Knot  

Diggersby @ Choice Scarf  
Ability: Huge Power  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Giga Impact  
- Earthquake  
- Ice Punch  
- Gunk Shot  

Heatran @ Custap Berry  
Ability: Flash Fire  
EVs: 56 HP / 232 SpA / 100 SpD / 120 Spe  
Modest Nature  
IVs: 0 Atk  
- Overheat  
- Flash Cannon  
- Dragon Pulse  
- Endure