Mortuary + Hangarback Walker + Fecundity

Mortuary

Hangarback Walker

Fecundity

How it works

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

This looping machinery sets up an infinite card-drawing and trigger engine by exploiting Hangarback Walker’s inherent vulnerability when cast for zero mana. Because Hangarback Walker enters the battlefield with zero toughness, it instantly dies as a state-based action, immediately sending both Mortuary and Fecundity into action. Mortuary ensures the dying artifact creature goes straight back to the top of your library rather than lingering in the graveyard, while Fecundity rewards that very same death by letting you draw it right back into your hand. By repeating this zero-mana cast-and-die cycle endlessly, you generate boundless leaves-the-battlefield events, enter-the-battlefield triggers, death triggers, storm count, and card draws.