turtle time

https://pokepast.es/582d93a41c8cf944

Pretty straight forward, I'm more or less trying to use some different picks here; we could very easily 4-man with Serperior

chocky chipp (Wo-Chien) @ Rocky Helmet
Role: Support
Your role is to stay alive and spam Tickle until the shield goes up. Your ability isn't variable, but it is also perfect as Torterra is a Physical attacker and all of your allies are Special Attackers.
Turn 1: Leech Seed - Passive healing that doesn't go away
Turn 2: Tickle - Reduces Torterra's Attack and Defense
Turn 3: Reflect - Increases the team's Defense
Giga Drain when the shield is up. Tera is good to get, but not required asap. Just use it for healing.

shayna love me (Serperior) @ Ability Shield
Ability: Contrary
Role: Attacker
Your role is to deal that big damage. Pretty straight forward. Contrary is key to this Pokemon.
Turn 1: Gasto Acid - This will negate Torterra's Shell Armor, meaning we can crit it now
Turn 2+: Leaf Storm.
Giga Drain when you need healing or run out of leaf storms.
Taunt may not be necessary.

Mila Tree (Arboliva) @ Terrain Extender
Ability: Seed Sower
Role: Support/Attacker
You're here to bring some grass.
Turn 1: Leech Seed - Passive healing that doesn't go away.
Turn 2+: Terrain Pulse if Grassy Terrain is active, Giga Drain if it isn't
Use Psych Up on Serperior or Sinistcha once they hit +6 Special Attack

coffee (Sinistcha-Masterpiece) @ Wide Lens
Ability: Hospitality
Role: Defender/Attacker
You're here for refreshments. Hospitality isn't ever going to really proc, but it's still the ideal
Turn 1: Iron Defense - Reduce the damage you take
Turn 2: Nasty Plot - Increase your damage output
Turn 3+: Matcha Gotcha - Heal & Deal massive damage
Strength Sap can be used for emergency healing, target Serperior (as Contrary will mean it will always heal you nearly to full)