Mortuary + Moldervine Reclamation + Bolas's Citadel + Myr Scrapling

Mortuary

Moldervine Reclamation

Bolas's Citadel

Myr Scrapling

How it works

1. Activate Myr Scrapling by sacrificing it.
2. When Myr Scrapling dies, Mortuary and Moldervine Reclamation trigger.
3. Resolve the Moldervine Reclamation trigger, causing you to gain 1 life and draw a card.
4. Resolve the Mortuary trigger, putting Myr Scrapling from your graveyard onto the top of your library.
5. Resolve the Myr Scrapling ability.
6. Cast Myr Scrapling from the top of your library by paying 1 life.
7. Repeat.

This loop transforms a humble Myr Scrapling into an engine of endless rebirth, using its own sacrifice ability to trigger a cascade of triggers. Because Mortuary redirects the dying automaton straight back to the top of your library, Moldervine Reclamation can safely draw it right back into your hand—or rather, keep it poised at the pinnacle of your deck. That precise positioning is the entire key to the operation, as Bolas's Citadel lets you bypass mana entirely and recast the creature directly off the top for a tiny pittance of life, more than cushioned by the life you regain along the way.