This elegant loop hinges on leveraging your upkeep step to establish an unstoppable engine of infinite turns. By casting Walk the Aeons to secure consecutive turns, you send the spell straight to your graveyard, where it waits to be reclaimed. When your next turn rolls around, Extravagant Replication triggers at the very beginning of your upkeep to churn out a fresh token copy of Ardent Elementalist. The arriving token immediately triggers its own ability, plucking Walk the Aeons right back out of your graveyard and back into your hand so you can cast it all over again.