Ditto @ Choice Scarf  
Ability: Imposter  
EVs: 252 HP / 252 Def / 4 SpD  
Impish Nature  
IVs: 30 Atk  
- Transform  

Necrozma-Dusk-Mane @ Weakness Policy  
Ability: Prism Armor  
EVs: 252 HP / 252 Def / 4 SpD  
Relaxed Nature  
- Heat Wave  
- Sunsteel Strike  
- Moonlight  
- Stealth Rock  

Zekrom @ Haban Berry  
Ability: Teravolt  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Roost  
- Dragon Claw  
- Bolt Strike  
- Dragon Dance  

Eternatus @ Haban Berry  
Ability: Pressure  
EVs: 252 HP / 240 Def / 16 Spe  
Timid Nature  
IVs: 0 Atk  
- Dynamax Cannon  
- Toxic  
- Flamethrower  
- Recover  

Ferrothorn @ Leftovers  
Ability: Iron Barbs  
EVs: 252 HP / 252 Def / 4 SpD  
Impish Nature  
- Leech Seed  
- Knock Off  
- Curse  
- Spikes  

Blissey (F) @ Heavy-Duty Boots  
Ability: Natural Cure  
EVs: 4 HP / 252 Def / 252 SpD  
Calm Nature  
IVs: 0 Atk  
- Confide  
- Thunder Wave  
- Soft-Boiled  
- Heal Bell