Requires

Kodama of the East Tree must be in hand, or in the command zone. Double Major must be in hand. Arid Archway must be in hand. Mana needed:

Steps

1. Cast Kodama of the East Tree by paying plus commander tax, if applicable.
2. Holding priority, cast Double Major by paying , copying the Kodama of the East Tree spell.
3. Resolve both Kodama of the East Tree spells, with the copy creating a nonlegendary token copy of Kodama of the East Tree.
4. Play Arid Archway.
5. Kodama of the East Tree, the Kodama of the East Tree token, and Arid Archway trigger.
6. Resolve the Kodama of the East Tree token's trigger, choosing not to put anything from your hand onto the battlefield.
7. Resolve the Arid Archway trigger, returning it to your hand.
8. Resolve the Kodama of the East Tree trigger, putting Arid Archway onto the battlefield.
9. The Kodama of the East Tree token and Arid Archway trigger.
10. Resolve the Arid Archway trigger, returning it to your hand.
11. Resolve the Kodama of the East Tree token's trigger, putting Arid Archway onto the battlefield.
12. Kodama of the East Tree and Arid Archway trigger.
13. Repeat from step 8.

Results