Gardevoir-Mega (F) @ Gardevoirite
Ability: Trace
EVs: 24 HP / 56 Def / 176 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Protect
- Hyper Voice
- Psyshock
- Taunt

Umbreon (M) @ Chesto Berry
Ability: Synchronize
EVs: 248 HP / 112 Def / 144 SpD / 4 Spe
Calm Nature
IVs: 0 Atk
- Toxic
- Taunt
- Foul Play
- Rest

Jirachi @ Choice Scarf
Ability: Serene Grace
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- U-turn
- Iron Head
- Fire Punch
- Healing Wish

Hippowdon @ Leftovers
Ability: Sand Stream
EVs: 248 HP / 144 Def / 116 SpD
Impish Nature
- Stealth Rock
- Earthquake
- Slack Off
- Stone Edge

Zapdos @ Rocky Helmet
Ability: Pressure
EVs: 248 HP / 176 Def / 68 SpA / 16 Spe
Bold Nature
IVs: 0 Atk
- Defog
- Volt Switch
- Heat Wave
- Roost

Azumarill @ Choice Band
Ability: Huge Power
EVs: 168 HP / 252 Atk / 88 Spe
Adamant Nature
- Aqua Jet
- Waterfall
- Play Rough
- Knock Off

I'm not sure if I want Hippowdon to have Whirlwind or Stone Edge, but I think it's fine.