Nice Nightmare

Ferrothorn (M) @ Rocky Helmet
Trait: Iron Barbs
EVs: 252 HP / 88 Def / 168 SDef
Relaxed Nature
- Gyro Ball
- Leech Seed
- Stealth Rock
- Thunder Wave

Dragonite (M) @ Lum Berry
Trait: Multiscale
EVs: 252 Atk / 252 Spd
Adamant Nature
- Outrage
- Extreme Speed
- Superpower
- Dragon Dance

Latias (F) @ Leftovers
Trait: Levitate
EVs: 72 HP / 184 SAtk / 252 Spd
Timid Nature
- Healing Wish
- Psyshock
- Draco Meteor
- Defog

Rotom-W @ Leftovers
Trait: Levitate
EVs: 240 HP / 252 Def / 16 Spd
Bold Nature
- Volt Switch
- Will-O-Wisp
- Hydro Pump
- Pain Split

Conkeldurr (M) @ Assault Vest
Trait: Guts
EVs: 228 HP / 252 Atk / 28 SDef
Adamant Nature
- Drain Punch
- Mach Punch
- Ice Punch
- Knock Off

Diancie @ Diancite
Trait: Clear Body
EVs: 24 Atk / 232 SAtk / 252 Spd
Naive Nature
- Moonblast
- Hidden Power [Fire]
- Diamond Storm
- Protect