Mortuary + Bolas's Citadel + Relic Vial + Myr Scrapling

Mortuary

Bolas's Citadel

Relic Vial

Myr Scrapling

How it works

1. Activate Myr Scrapling by sacrificing it.
2. When Myr Scrapling dies, Mortuary and Relic Vial trigger.
3. Resolve the Mortuary trigger, putting Myr Scrapling from your graveyard onto the top of your library.
4. Resolve the Relic Vial trigger, causing you to gain 1 life and each opponent to lose 1 life.
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 insect into an endless engine of attrition by turning your library into a looping deck-top workshop. With Bolas's Citadel providing the vital vantage point and life-payment mechanism to cast spells directly from the top of your library, Myr Scrapling can be repeatedly sacrificed and recast for a mere single life point. Every time the Scrapling meets its end, Mortuary steps in to catch it on its way to the graveyard, instantly placing it right back on top of your library for the Citadel to grab again. Meanwhile, Relic Vial rewards this endless cycle by draining your opponents and padding your life total, ensuring that the life you pay into Bolas's Citadel is more than replenished with every iteration.