Mortuary + Vivien, Monsters' Advocate + Shifting Wall

Mortuary

Vivien, Monsters' Advocate

Shifting Wall

How it works

1. Cast Shifting Wall either from your hand or from the top of your library by paying 0.
2. Shifting Wall enters the battlefield and dies as a state-based action due to having zero toughness.
3. Mortuary triggers, putting Shifting Wall on top of your library from your graveyard.
4. Repeat.

This elegant loop turns a casting cost of zero into an endless engine of creature activity. By casting Shifting Wall for $0$, you instantly bypass the mana restriction normally required to fuel a sacrifice loop; because it enters with zero toughness, it hits the graveyard immediately as a state-based action. From there, Mortuary acts as the conveyor belt, quietly intercepting the dying creature and placing it directly back onto the top of your library. Finally, Vivien, Monsters' Advocate completes the puzzle by letting you look at that very top card and cast Shifting Wall over and over again from the library, generating an endless cascade of enters-the-battlefield, leaves-the-battlefield, and death triggers.