Groudon @ Leftovers  
Ability: Drought  
EVs: 248 HP / 200 Def / 44 SpD / 16 Spe  
Impish Nature  
- Earthquake  
- Stealth Rock  
- Lava Plume  
- Thunder Wave  

Volcarona @ Heavy-Duty Boots  
Ability: Flame Body  
EVs: 248 HP / 244 Def / 16 Spe  
Timid Nature  
IVs: 0 Atk  
- Flamethrower  
- Quiver Dance  
- Roost  
- Safeguard  

Necrozma-Dusk-Mane @ Shed Shell  
Ability: Prism Armor  
EVs: 248 HP / 84 Atk / 144 SpD / 32 Spe  
Careful Nature  
- Sunsteel Strike  
- Morning Sun  
- Knock Off  
- Swords Dance  

Yveltal @ Heavy-Duty Boots  
Ability: Dark Aura  
EVs: 232 HP / 252 SpD / 24 Spe  
Calm Nature  
IVs: 0 Atk  
- Foul Play  
- Oblivion Wing  
- Roost  
- Defog  

Eternatus @ Black Sludge  
Ability: Pressure  
EVs: 248 HP / 216 SpD / 44 Spe  
Calm Nature  
IVs: 0 Atk  
- Flamethrower  
- Dynamax Cannon  
- Sludge Bomb  
- Recover  

Skarmory @ Shed Shell  
Ability: Sturdy  
EVs: 248 HP / 244 Def / 16 Spe  
Bold Nature  
IVs: 0 Atk  
- Spikes  
- Whirlwind  
- Roost  
- Counter