Requires

Mythos of Illuna must be in hand. Radiate must be in hand. Greenwarden of Murasa must be on the battlefield. Enough lands or other mana producers total among all players which can be activated the turn they enter the battlefield to produce at least (this condition is trivially easy). Mana needed:

Steps

1. Cast Mythos of Illuna targeting anything but Greenwarden, holding priority, and then cast Radiate targeting Mythos of Illuna.
2. When Radiate resolves you will have Mythos copies targeting every targetable permanent (except what the original Mythos card is targeting).
3. When each of the copies resolve, target Radiate in your graveyard with the new Greenwarden token's ability and return Radiate to your hand.
4. Before the original Mythos of Illuna card resolves, cast Radiate again targeting Mythos by spending mana from the tokens you just created.
5. Repeat this process, effectively doubling the number of copies created, allowing you to return Radiate and another card with two Greenwarden triggers.
6. Repeat.

Results