Heatran @ Custap Berry  
Ability: Flash Fire  
EVs: 88 HP / 120 SpA / 192 SpD / 108 Spe  
Modest Nature  
IVs: 0 Atk  
- Flamethrower  
- Ancient Power  
- Endure  
- Flash Cannon  

Altaria-Mega @ Altarianite  
Ability: Pixilate  
EVs: 212 HP / 168 Atk / 28 SpD / 100 Spe  
Adamant Nature  
- Dragon Dance  
- Giga Impact  
- Earthquake  
- Roost  

Mew @ Absorb Bulb  
Ability: Synchronize  
EVs: 252 SpA / 4 SpD / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Taunt  
- Thunderbolt  
- Soft-Boiled  
- Will-O-Wisp