Glacial Chasm, Azusa, Lost but Seeking, and Ancient Greenwarden

Prerequisites

• Glacial Chasm in hand or in the graveyard
• Azusa, Lost but Seeking on the battlefield
• Ancient Greenwarden on the battlefield
• You control at least two additional lands

Steps

1. Play Glacial Chasm either from your hand or from your graveyard
2. When Glacial Chasm enters the battlefield, its second ability triggers twice, causing you to sacrifice two other lands you control
3. Pass the turn
4. At the beginning of your next upkeep, Glacial Chasm's cumulative upkeep ability triggers, causing you to sacrifice it
5. Play two lands except Glacial Chasm from your graveyard
6. Repeat

Results

• Prevent all damage that would be dealt to you