Retreat to Coralhelm, Ghost Town, and Skyshroud Ranger

Prerequisites

• Retreat to Coralhelm on the battlefield
• Ghost Town in hand
• Skyshroud Ranger on the battlefield

Steps

1. During any opponent's turn, activate Skyshroud Ranger by tapping it, putting Ghost Town from your hand onto the battlefield
2. When Ghost Town enters the battlefield, Retreat to Coralhelm triggers, untapping Skyshroud Ranger
3. Activate Ghost Town's first ability by tapping it, adding
4. Activate Ghost Town's second ability by paying , returning it from the battlefield to your hand
5. Repeat

Results

• Infinite landfall triggers
• Infinite colorless mana during each opponent's turn