Turn 3:
Mellow: Soothe I on Celeste
Zane: Final Rush -> Radiant Ridicule on Nip (You can't predict aggro so I'm getting a good guess), Focus, Luminous Orb, Oran
Cynthian: Elixir+Elixir, Growthx2
Cino: After You on Dave
Bahamut: Call Astrid
Celeste: Double Radiant Vision
Vix: Elixir, Heat Wave x2
Nip: Lash Out Shaymin x3
Dave: Focus, Elixir+Elixir, Assurance x2 on Shaymin Horde
Starr: Leech Life, Flare Blitz on Shaymin or FBx2 if not stalled, then Elixir and Escape Orb.
Curio: Drain Punch Shaymin, Oran Berry, Radiant Fist Shaymin
Astrid: Radiant Iceberg Machine, Psych Up Cynthian, Elixir+Elixir