Mortuary + Ugin's Conjurant + Fecundity

Mortuary

Ugin's Conjurant

Fecundity

How it works

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

This brilliant loop turns the zero-cost casting of Ugin's Conjurant into an engine that cycles your entire deck. Because Ugin's Conjurant enters the battlefield with no toughness when cast for free, state-based actions send it straight to the graveyard, triggering both Mortuary and Fecundity simultaneously. Mortuary ensures that Ugin's Conjurant never stays in the graveyard by instantly placing it back on top of your library, while Fecundity rewards that death by letting you draw it right back into your hand.