Ditto @ Choice Scarf  
Ability: Imposter  
EVs: 252 HP / 4 Atk / 252 Def  
Relaxed Nature  
IVs: 0 Spe  
- Transform  

Kyogre-Primal @ Blue Orb  
Ability: Primordial Sea  
EVs: 72 Def / 184 SpA / 252 Spe  
Modest Nature  
IVs: 0 Atk  
- Origin Pulse  
- Ice Beam  
- Calm Mind  
- Thunder  

Mewtwo-Mega-Y @ Mewtwonite Y  
Ability: Pressure  
EVs: 40 Def / 216 SpA / 252 Spe  
Timid Nature  
IVs: 0 Atk  
- Psystrike  
- Nasty Plot  
- Ice Beam  
- Flamethrower  

Meganium @ Leftovers  
Ability: Leaf Guard  
EVs: 248 HP / 252 Def / 8 SpD  
Bold Nature  
IVs: 0 Atk  
- Toxic  
- Synthesis  
- Aromatherapy  
- Magic Coat  

Landorus (M) @ Choice Band  
Ability: Sand Force  
EVs: 252 Atk / 4 SpD / 252 Spe  
Jolly Nature  
- Earthquake  
- Knock Off  
- Superpower  
- Stealth Rock  

Xerneas @ Power Herb  
Ability: Fairy Aura  
EVs: 168 HP / 252 SpA / 88 Spe  
Modest Nature  
IVs: 0 Atk  
- Moonblast  
- Geomancy  
- Thunder  
- Hidden Power [Fire]