All at level 100

Mewtwo-Mega-X @ Choice Band  
Ability: Adaptability  
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe  
Naughty Nature  
- Close Combat  
- Thousand Arrows  
- Ice Beam  
- Poison Jab

Kyogre-Primal @ Choice Scarf  
Ability: Primordial Sea  
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe  
Mild Nature  
- Water Spout  
- Ice Beam  
- Sucker Punch  
- Thousand Arrows

Xerneas @ Choice Specs  
Ability: Fairy Aura  
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe  
Rash Nature  
- Moonblast  
- Fusion Flare  
- Psystrike  
- Close Combat

Slaking @ Choice Scarf  
Ability: No Guard  
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe  
Naive Nature  
- Blizzard  
- Close Combat  
- Sucker Punch  
- Thousand Arrows

Thundurus (M) @ Choice Scarf  
Ability: No Guard  
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe  
Naive Nature  
- Blizzard  
- Thunder  
- Focus Blast  
- Thousand Arrows

Scizor-Mega @ Choice Band  
Ability: Primordial Sea  
EVs: 252 HP / 252 Atk / 252 Def / 252 SpA / 252 SpD / 252 Spe  
Naive Nature  
- X-Scissor  
- Thousand Arrows  
- Close Combat  
- Ice Punch