Retreat to Coralhelm + Scaled Herbalist + Selesnya Sanctuary

Retreat to Coralhelm

Scaled Herbalist

Selesnya Sanctuary

How it works

1. Activate Scaled Herbalist by tapping it, putting Selesnya Sanctuary from your hand onto the battlefield.
2. When Selesnya Sanctuary enters the battlefield, it and Retreat to Coralhelm trigger.
3. Resolve the Selesnya Sanctuary trigger, returning itself from the battlefield to your hand.
4. Resolve the Retreat to Coralhelm trigger, untapping Scaled Herbalist.
5. Repeat.

This clever loop turns a simple bounce land into a self-sustaining engine by exploiting the interaction between Scaled Herbalist and Retreat to Coralhelm. When you use Scaled Herbalist to drop Selesnya Sanctuary onto the battlefield, the Sanctuary's own enter-the-battlefield trigger forces you to return it right back to your hand. Simultaneously, that land entry triggers Retreat to Coralhelm, whose landfall ability untaps Scaled Herbalist so you can immediately repeat the process. Because Selesnya Sanctuary bounces itself directly to your hand instead of staying in play, you can endlessly replay it to generate infinite landfall triggers.