Petilil chain steps

SETUP
1. Breed four Gothita eggs in Sun.
2. Trade them to Moon as they are close to hatching.
3. Hatch the eggs in Moon.
4. Trade the Gothita back to Sun.
5. Level up the Gothita to lv40. Make sure their movesets include Heal Block and Pound.
6. Teach all four Gothita Thunder Wave and Substitute.
7. Trade all four Gothita back to Moon.
8. Trade Trevenant to Moon holding a Leppa Berry.
9. Trade Decidueye to Moon holding an Adrenaline Orb.
10. In Moon, remove the Adrenaline Orb from Decidueye.

CHAINING
1. Set party order to: Trevenant, Decidueye, Gothita, Gothita, Gothita, Gothita.
2. Encounter a Petilil in Melemele Meadow (30%, lv9-12)
3. Bestow Leppa Berry onto Petilil.
4. Skill Swap Harvest onto Petilil.
5. Switch to Decidueye.
6. False Swipe Petilil to 1 HP.
7. Use the Adrenaline Orb.
8a. Switch to the first Gothita.
8b. If the first Gothita is Leech Seeded, switch back to Decidueye and use False Swipe.
8c. Once the opposing Petilil is back down to 1 HP, switch to the first Gothita again.
8d. Repeat 8b and 8c until the Gothita is not affected by Leech Seed.
9. Use Substitute.
10. If Gothita is paralyzed, use a Paralyze Heal.

Use Heal Block every five turns. Use Pound to knock out the called Pokémon. If a shiny is called, knock out the caller, then use Thunder Wave to stop the shiny from calling allies. Otherwise, when Gothita runs out of PP on Pound, repeat 8a to 10 with the second, third and fourth Gothita as needed. If the fourth Gothita runs out of PP on Pound, soft reset and restart the chain at Chaining step 1.