Dragapult @ Choice Specs  
Ability: Infiltrator  
EVs: 252 SpA / 4 SpD / 252 Spe  
Modest Nature  
- Shadow Ball  /  Hex
- Draco Meteor  
- U-turn  
- Flamethrower  /  Thunderbolt  /  Will-O-Wisp

PLUS

Blacephalon @ Choice Scarf
Ability: Beast Boost  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature  
- Shadow Ball  
- Flamethrower  
- Overheat  /  Toxic
- Trick  

OR

Blacephalon @ Choice Specs
Ability: Beast Boost  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature  
- Shadow Ball  
- Flamethrower  
- Overheat  /  Toxic
- Trick