Volcanion OU that's probably weak to something

Volbaenion (Volcanion) @ Choice Specs
Ability: Water Absorb
EVs: 72 HP / 252 SpA / 184 Spe
Modest Nature
IVs: 0 Atk
- Steam Eruption
- Fire Blast
- Earth Power
- Sludge Bomb

Cow (Raikou) @ Assault Vest
Ability: Pressure
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk / 30 Def
- Volt Switch
- Thunderbolt
- Hidden Power [Ice]
- Shadow Ball

birb (Skarmory) @ Rocky Helmet
Ability: Sturdy
EVs: 248 HP / 236 Def / 24 Spe
Impish Nature
- Stealth Rock
- Spikes
- Roost
- Brave Bird

Dentist (Excadrill) @ Choice Scarf
Ability: Mold Breaker
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Earthquake
- Iron Head
- Rock Slide
- Rapid Spin

notloc (Latios) @ Life Orb
Ability: Levitate
EVs: 252 SpA / 12 SpD / 244 Spe
Timid Nature
IVs: 0 Atk / 30 SpA / 30 Spe
- Draco Meteor
- Psyshock
- Hidden Power [Fire]
- Roost

wendy (Altaria-Mega) @ Altarianite
Ability: Natural Cure
EVs: 248 HP / 136 Def / 96 SpD / 28 Spe
Impish Nature
- Return
- Dragon Dance
- Roost
- Heal Bell