Mortuary + Realmwalker + Stonecoil Serpent

Mortuary

Realmwalker

Stonecoil Serpent

How it works

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

This clever loop turns a zero-mana artifact creature into an endless engine of sacrifice and rebirth. By choosing "Serpent" as Realmwalker enters, its passive ability grants you the vital permission to continuously cast Stonecoil Serpent straight off the top of your library for zero mana. As soon as that Serpent hits the battlefield, state-based actions send it immediately to the graveyard with zero toughness, which instantly triggers Mortuary to place the Serpent right back onto the top of your library. Repeating this seamless cycle generates an endless stream of creature enters-the-battlefield, leaves-the-battlefield, and death triggers to fuel your victory.