Play Glacial Chasm either from your hand or from your graveyard.
When Glacial Chasm enters the battlefield, its second ability triggers, causing you to sacrifice another land you control.
Play any land from your graveyard.
At 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.
Repeat.
By anchoring our defense behind Glacial Chasm, we completely insulate ourselves from all incoming damage while gracefully dodging its painful cumulative upkeep and attack restrictions by simply letting it sacrifice itself. To keep the loop flowing, Walk-In Closet // Forgotten Cellar steps in to let us repeatedly play lands straight from our graveyard. Meanwhile, Wayward Swordtooth ensures we have the extra land drop each turn required to keep replaying that Chasm, letting us lock opponents out of dealing damage turn after turn.