Retreat to Coralhelm + Walking Atlas + Dimir Aqueduct

Retreat to Coralhelm

Walking Atlas

Dimir Aqueduct

How it works

1. Activate Walking Atlas by tapping it, putting Dimir Aqueduct from your hand onto the battlefield.
2. When Dimir Aqueduct enters the battlefield, it and Retreat to Coralhelm trigger.
3. Resolve the Dimir Aqueduct trigger, returning itself from the battlefield to your hand.
4. Resolve the Retreat to Coralhelm trigger, untapping Walking Atlas.
5. Repeat.

This clever loop turns a simple bounce land into an infinite engine by leveraging Retreat to Coralhelm's landfall trigger every time a land enters the battlefield. By using Walking Atlas to drop Dimir Aqueduct directly from your hand, you trigger both the land's own return-to-hand clause and the enchantment's untap ability. Resolving Dimir Aqueduct's trigger sends it right back to your hand so you can replay it, while the Retreat to Coralhelm trigger readies Walking Atlas for the next iteration.