Mortuary + Fecundity + Walking Ballista

Mortuary

Fecundity

Walking Ballista

How it works

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

By casting Walking Ballista for zero mana, state-based actions immediately send it to the graveyard, triggering both Mortuary and Fecundity simultaneously. Mortuary ensures that the fallen automaton doesn't stay in the dirt, neatly placing it back on top of your library instead, while Fecundity rewards that very same death by letting you draw it right back into your hand. This creates a relentless, self-sustaining loop that endlessly recycles your threats while churning through your entire deck, racking up infinite creature leaves-the-battlefield, enters-the-battlefield, and death triggers along the way.