Retreat to Coralhelm, Arid Archway, and Llanowar Scout

Prerequisites

• Retreat to Coralhelm on the battlefield
• Arid Archway in hand
• Llanowar Scout on the battlefield

Steps

1. Activate Llanowar Scout by tapping it, putting Arid Archway from your hand onto the battlefield
2. When Arid Archway enters the battlefield, it and Retreat to Coralhelm trigger
3. Resolve the Arid Archway trigger, returning itself from the battlefield to your hand
4. Resolve the Retreat to Coralhelm trigger, untapping Llanowar Scout
5. Repeat

Results

• Infinite landfall triggers