Diancie @ Leftovers Ability: Clear Body Tera Type: Water EVs: 252 HP / 4 Atk / 252 SpD Careful Nature - Diamond Storm - Body Press - Play Rough - Protect Ho-Oh @ Clear Aumelet Ability: Regenerator Tera Type: Grass EVs: 204 HP / 76 Atk / 156 Def / 4 SpD / 68 Spe Adamate Nature - Sacred Fire - Brave Bird - Tailwind - Protect Rillaboom @ Aussalt Vest Ability: Grassy Surge Tera Type: Fire EVs: 252 HP / 36 Atk / 76 Def / 124 SpD / 20 Spe Adamate Nature - Fake Out - Wood Hammer - Grassy Glide - U-Turn Ogerpon-Wellspring @ Wellspring Mask Ability: Water Absorb Tera Type: Water EVs: 236 HP / 236 Def / 36 SpD Impish Nature - Follow Me - Spiky Shield - Ivy Crugel - Horn Leech Raging Bolt @ Booster Energy Ability: Protosynthesis Level: 50 Tera Type: Bug EVs: 188 HP / 108 Def / 180 SpA / 20 SpD / 12 Spe Modest Nature - Thundercalp - Taunt - Electroweb - Protect Gholdengo @ Life Orb Ability: Good As Gold Level: 50 Tera Type: Steel EVs: 204 HP / 44 Def / 180 SpA / 36 SpD / 68 Spe Modest Nature - Make It Rain - Shadow Ball - Nasty Plot - Protect
Do NOT use Tailwind to support Diancie. Daincie is too slow to benefit from tailwind, so it's just a wasted turn. Only bring Gholdengo if it has a very good matchup against your opponent, because Gholdengo can sometimes be unreliable.