Team Essencial Pokémon:

• Overlord / Resonance Diancie
• Overlord Tapu Fini

Possible Teammates:

• Overlord Xerneas
• Spotlight Pokémon

Teammate Explanation:

Overlord Xerneas:
This pokémon only exists there to increase his other teammate's potential in the battle. His passive will increase the Fairy Type Pokémon's damage, and Overlord Tapu Fini's weather buff will also become much better just for having Overlord Xerneas in the team.

Spotlight Pokémon:
Any pokémon that has his first ability of Spotlight. Usually Earth Devil or Crystal Onix. The main goal is to deny single-target attackers from attacking your Diancie directly