Scaretiller, Retreat to Coralhelm, and Maestros Theater

Prerequisites

• Scaretiller on the battlefield
• Retreat to Coralhelm on the battlefield
• Maestros Theater in hand
• Scaretiller is untapped
• You have a basic Island, Mountain, or Swamp in library

Steps

1. Play Maestros Theater
2. Maestros Theater enters the battlefield, triggering itself and Retreat to Coralhelm
3. Resolve the Maestros Theater trigger, causing you to sacrifice it, then search your library for a basic Mountain, Swamp or Island card, put it onto the battlefield tapped, and gain 1 life
4. The basic land enters the battlefield, triggering Retreat to Coralhelm, tapping Scaretiller
5. Scaretiller triggers, returning Maestros Theater from your graveyard to the battlefield tapped
6. Maestros Theater enters the battlefield, triggering itself and Retreat to Coralhelm
7. Resolve the Retreat to Coralhelm trigger, untapping Scaretiller
8. Repeat from step 3

Results

• Near-infinite landfall triggers
• Near-infinite lifegain
• Near-infinite lifegain triggers
• Put all basic Swamps, Islands, and Mountains from your library onto the battlefield tapped