Scaretiller, Retreat to Coralhelm, and Riveteers Overlook

Prerequisites

• Scaretiller on the battlefield
• Retreat to Coralhelm on the battlefield
• Riveteers Overlook in hand
• Scaretiller is untapped
• You have a basic Forest, Mountain, or Swamp in library

Steps

1. Play Riveteers Overlook
2. Riveteers Overlook enters the battlefield, triggering itself and Retreat to Coralhelm
3. Resolve the Riveteers Overlook trigger, causing you to sacrifice it, then search your library for a basic Mountain, Swamp or Forest 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 Riveteers Overlook from your graveyard to the battlefield tapped
6. Riveteers Overlook 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, Forests, and Mountains from your library onto the battlefield tapped