Mega Doomsday

Houndoom-Mega @ Houndoominite
Ability: Flash Fire
EVs: 4 Atk / 252 SpA / 252 Spe
Naive Nature
- Dark Pulse
- Fire Blast
- Sucker Punch
- Sludge Bomb

Oricorio-Sensu @ Choice Scarf
Ability: Dancer
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- U-turn
- Revelation Dance
- Hurricane
- Hidden Power [Rock]

Keldeo-Resolute @ Choice Specs
Ability: Justified
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Scald
- Secret Sword
- Icy Wind
- Hidden Power [Grass]

Tapu Lele @ Assault Vest
Ability: Psychic Surge
EVs: 4 HP / 252 SpA / 104 SpD / 148 Spe
Modest Nature
IVs: 0 Atk
- Moonblast
- Psyshock
- Thunderbolt
- Psychic

Omastar @ Focus Sash
Ability: Weak Armor
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Stealth Rock
- Spikes
- Toxic Spikes
- Icy Wind

Thundurus @ Flyinium Z
Ability: Defiant
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Knock Off
- Fly
- Wild Charge
- Superpower