Heatran @ Shed Shell  
Ability: Magic Bounce  
EVs: 248 HP / 4 SpA / 252 SpD  
Modest Nature  
IVs: 0 Atk  
- Baton Pass  
- Roost  
- Taunt  
- Doom Desire  

Slaking @ Life Orb  
Ability: Shadow Tag  
EVs: 252 Atk / 252 Def / 4 SpD  
Adamant Nature  
- Fake Out  
- Extreme Speed  
- Low Kick  
- Water Shuriken  

Rayquaza-Mega @ Choice Specs  
Ability: Gale Wings  
EVs: 248 HP / 252 SpA / 4 SpD / 4 Spe  
Modest Nature  
IVs: 0 Atk  
- Oblivion Wing  
- Chatter  
- Trick  
- Spikes  

Xerneas @ Leftovers  
Ability: Wonder Guard  
EVs: 4 Def / 252 SpA / 252 Spe  
Modest Nature  
IVs: 0 Atk  
- Substitute  
- Baton Pass  
- Moonblast  
- Taunt  

Blissey (F) @ Shed Shell  
Ability: Wonder Guard  
EVs: 248 HP / 8 Def / 252 SpD  
Sassy Nature  
IVs: 0 Atk / 0 Spe  
- Baton Pass  
- Whirlwind  
- Roost  
- Defog  

Rayquaza-Mega @ Shed Shell  
Ability: Mold Breaker  
EVs: 64 HP / 252 SpA / 192 Spe  
Modest Nature  
IVs: 0 Atk  
- Shell Smash  
- Earth Power  
- Oblivion Wing  
- Dark Void