Fairium Xerneas + Mega Gengar Bulky Offense Team

Reshiram @ Choice Scarf
Ability: Turboblaze
Shiny: Yes
EVs: 4 Atk / 252 SpA / 252 Spe
Modest Nature
- Blue Flare
- Earth Power
- Draco Meteor
- Stone Edge

Arceus-Water @ Splash Plate
Ability: Multitype
EVs: 252 HP / 168 Def / 88 Spe
Bold Nature
IVs: 0 Atk
- Judgment
- Toxic
- Recover
- Defog

Groudon-Primal @ Red Orb
Ability: Desolate Land
Shiny: Yes
EVs: 252 HP / 44 Atk / 212 SpD
Careful Nature
- Stealth Rock
- Precipice Blades
- Roar
- Fire Punch

Ho-Oh @ Life Orb
Ability: Regenerator
Shiny: Yes
EVs: 248 HP / 208 Atk / 52 SpD
Adamant Nature
- Roost
- Sacred Fire
- Brave Bird
- Earthquake

Xerneas @ Fairium Z
Ability: Fairy Aura
Shiny: Yes
EVs: 252 HP / 240 Def / 16 Spe
Bold Nature
IVs: 0 Atk
- Geomancy
- Sleep Talk
- Rest
- Moonblast

Gengar-Mega @ Gengarite
Ability: Shadow Tag
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Focus Blast
- Sludge Wave
- Shadow Ball
- Substitute