Omnath, Locus of the Roil, Abundance, Retreat to Coralhelm, and Walking Atlas

Prerequisites

• Omnath, Locus of the Roil on the battlefield
• Abundance on the battlefield
• Retreat to Coralhelm on the battlefield
• Walking Atlas on the battlefield
• Walking Atlas does not have summoning sickness
• You have a land card in hand
• You control at least seven lands

Steps

1. Activate Walking Atlas by tapping it, putting a land card from your hand onto the battlefield
2. When the land enters the battlefield, Retreat to Coralhelm and Omnath's second ability triggers
3. Resolve the Retreat to Coralhelm trigger, untapping Walking Atlas
4. Resolve the Omnath trigger, putting a +1/+1 counter on an Elemental you control, and then causing you to reveal cards from the top of your library until you reveal a land card and put it into your hand due to Abundance
5. Repeat

Results

• Near-infinite landfall triggers
• Put all lands from your hand and library onto the battlefield