Mortuary + Harvester of Souls + Shifting Wall

Mortuary

Harvester of Souls

Shifting Wall

How it works

1. Cast Shifting Wall by paying 0.
2. Shifting Wall enters and dies as a state-based action due to having 0 toughness, triggering Mortuary and Harvester of Souls.
3. Resolve the Mortuary trigger, putting Shifting Wall from your graveyard onto the top of your library.
4. Resolve the Harvester of Souls trigger, causing you to draw a card, thus drawing Shifting Wall from your library.
5. Repeat.

This clever loop relies on the zero-mana casting cost of Shifting Wall, which enters the battlefield with no toughness and instantly perishes as a state-based action. That instant demise triggers Mortuary to seamlessly recycle the creature straight back to the top of your library. Meanwhile, Harvester of Souls sits ready on the board to capitalize on every single sacrifice, turning each death into a fresh card draw that puts Shifting Wall right back in your hand for zero mana.