Marshadow @ Choice Band  
Ability: Technician  
EVs: 252 Atk / 4 SpD / 252 Spe  
Adamant Nature  
- Poltergeist  
- Spectral Thief  
- Close Combat  
- Shadow Sneak  

Groudon @ Leftovers  
Ability: Drought  
EVs: 248 HP / 224 Def / 36 Spe  
Impish Nature  
- Precipice Blades  
- Stealth Rock  
- Toxic  
- Stone Edge  

Ferrothorn @ Leftovers  
Ability: Iron Barbs  
EVs: 248 HP / 8 Atk / 252 Def  
Impish Nature  
IVs: 0 Atk  
- Body Press  
- Iron Defense  
- Spikes  
- Leech Seed  

Yveltal @ Heavy-Duty Boots  
Ability: Dark Aura  
EVs: 16 HP / 240 SpD / 252 Spe  
Timid Nature  
- Knock Off  
- U-turn  
- Roost  
- Defog  

Necrozma-Dusk-Mane @ Rocky Helmet  
Ability: Prism Armor  
EVs: 248 HP / 136 Def / 120 Spe  
Impish Nature  
- Dragon Dance  
- Sunsteel Strike  
- Earthquake  
- Morning Sun  

Blissey (F) @ Utility Umbrella  
Ability: Natural Cure  
EVs: 4 HP / 252 Def / 252 SpD  
Sassy Nature  
IVs: 0 Atk  
- Seismic Toss  
- Aromatherapy  
- Soft-Boiled  
- Teleport