Glacial Chasm + Ramunap Excavator + Oracle of Mul Daya

Prerequisites

• You control another land.

Steps

1. 1Play Glacial Chasm either from your hand or from your graveyard.
2. 2When Glacial Chasm enters the battlefield, its second ability triggers, causing you to sacrifice another land you control.
3. 3Play any land from your graveyard.
4. 4At the beginning of your next upkeep, Glacial Chasm's cumulative upkeep ability triggers, allowing you to choose not to pay the cost and sacrifice it instead.
5. 5Repeat.

Effects

• Lock
• Prevent all damage that would be dealt to you