In the long run, a bulkier Relaxed Torterra has the most potential because it can stay on the field longer to set up with Curse, Swords Dance, or Iron Defense and heal up with Synthesis or Leech Seed.
As you may have expected if you have any experience with Pokémon games or the DLC for Sword & Shield, there is still plenty more to do in the Indigo Disk DLC after the credits have rolled. In fact, ...