Slaking @ Choice Band  
Ability: Truant  
Level: 50  
EVs: 4 HP / 252 Atk / 252 Spe  
Adamant Nature  
- Double-Edge  
- Shadow Ball  
- Earthquake  
- Hyper Beam  

Latios @ Lum Berry  
Ability: Levitate  
Level: 50  
EVs: 28 HP / 252 SpA / 228 Spe  
Modest Nature  
IVs: 0 Atk  
- Psychic  
- Ice Beam  
- Thunderbolt  
- Calm Mind  

Blissey @ Leftovers  
Ability: Natural Cure  
Level: 50  
EVs: 172 HP / 252 Def / 84 Spe  
Impish Nature  
IVs: 0 Atk  
- Seismic Toss  
- Toxic  
- Soft-Boiled  
- Aromatherapy