Zask, Skittering Swarmlord + Azusa, Lost but Seeking + Glacial Chasm

Zask, Skittering Swarmlord

Azusa, Lost but Seeking

Glacial Chasm

How it works

1. Play Glacial Chasm either from your hand or from your graveyard.
2. When Glacial Chasm enters the battlefield, its second ability triggers, causing you to sacrifice another land 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 a land except Glacial Chasm from your graveyard.
6. Repeat.

This clever lock relies on the damage-prevention prowess of Glacial Chasm to keep you completely safe, while Azusa, Lost but Seeking provides the extra land drops necessary to feed the cycle. Whenever the cumulative upkeep forces you to sacrifice Glacial Chasm, Zask, Skittering Swarmlord steps in to let you play lands directly out of your graveyard. By replaying the Chasm turn after turn, you bypass its mounting life payment entirely while continuously resetting its entry sacrifice trigger with whatever expendable land you have to spare.