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

Mewtwo-Mega-X @ Choice Scarf  
Ability: Shadow Tag  
EVs: 252 Atk / 232 Def / 24 Spe  
Adamant Nature  
- Ice Punch  
- Dragon Ascent  
- Low Kick  
- Knock Off  

Mewtwo-Mega-X @ Choice Band  
Ability: Illusion  
EVs: 252 Atk / 4 SpD / 252 Spe  
Adamant Nature  
- Gear Grind  
- Shadow Sneak  
- Close Combat  
- Trick  

Blissey (F) @ Leftovers  
Ability: Wonder Guard  
EVs: 248 HP / 8 Def / 252 SpD  
Sassy Nature  
IVs: 0 Atk / 0 Spe  
- Parting Shot  
- Magic Coat  
- Roost  
- Aromatherapy  

Shaymin @ Lum Berry  
Ability: Prankster  
EVs: 252 HP / 252 Def / 4 SpD  
Bold Nature  
IVs: 0 Atk  
- Spore  
- Destiny Bond  
- Encore  
- Roost  

Rayquaza-Mega @ Choice Specs  
Ability: Mold Breaker  
EVs: 252 SpA / 4 SpD / 252 Spe  
Modest Nature  
IVs: 0 Atk  
- Spacial Rend  
- Volt Switch  
- Chatter  
- Oblivion Wing