This is your team but fixed:
Lunala @ Lunalium Z
Ability: Shadow Shield
Timid Nature
252 Spe/252 SpA/4 Def
IVs: 0 Atk
- Calm Mind
- Moongeist Beam
- Focus Blast
- Psyshock
Groudon-Primal @ Red Orb
Ability: Drought --> Desolate Land
Relaxed Nature
252 HP/56 Def/200 SpD
- Stealth Rocks
- Overheat
- Precipice Blades
- Toxic
Rayquaza-Mega @ Life Orb
Ability: Air Lock --> Delta Stream
Jolly Nature
252 Spe/252 Atk/4 Def
- Dragon Dance
- Dragon Ascent
- Earthquake
- Extreme Speed
Marshadow @ Life orb
Ability: Technician
Jolly Nature
252 Spe/252 Atk/4 Def
- Shadow Sneak
- Spectral Thief
- Close Combat
- Rock Tomb
Xerneas @ Power Herb
Ability: Fairy Aura
Modest Nature
252 SpA/172 Def/84 Spe
IVs: 0 Atk
- Moonblast
- Geomancy
- Focus Blast
- Hidden Power (Rock)
Arceus @ Normalium Z
Ability: Multitype
Adamant Nature
EVs: 252 Atk/124 Spe/132 HP
- Swords Dance
- Extreme Speed
- Shadow Claw
- Refresh