It's a bird, It's a plane, it's Mega Latias

Latias @ Latiasite
Ability: Levitate
EVs: 248 HP / 84 Def / 176 Spe
Bold Nature
- Calm Mind
- Roost
- Reflect Type
- Stored Power

Chesnaught @ Leftovers
Ability: Bulletproof
EVs: 252 HP / 252 Def / 4 SpD
Impish Nature
- Leech Seed
- Drain Punch
- Spikes
- Spiky Shield

Tentacruel @ Black Sludge
Ability: Liquid Ooze
EVs: 248 HP / 216 Def / 28 SpD / 16 Spe
Timid Nature
- Scald
- Rapid Spin
- Acid Spray
- Toxic Spikes

Hippowdon @ Leftovers
Ability: Sand Force
EVs: 252 HP / 144 Def / 112 SpD
Impish Nature
- Earthquake
- Stealth Rock
- Slack Off
- Stone Edge

Clefable @ Leftovers
Ability: Unaware
EVs: 248 HP / 252 Def / 8 SpD
Bold Nature
- Calm Mind
- Moonblast
- Moonlight
- Heal Bell

Jirachi @ Leftovers
Ability: Serene Grace
EVs: 252 HP / 224 SpD / 32 Spe
Careful Nature
- Iron Head
- Toxic
- Wish
- Protect