Mortuary + Fleshtaker + Bolas's Citadel + Fanatical Firebrand

Mortuary

Fleshtaker

Bolas's Citadel

Fanatical Firebrand

How it works

1. Activate Fanatical Firebrand by tapping and sacrificing it.
2. When Fanatical Firebrand dies, Mortuary and Fleshtaker trigger.
3. Resolve the Fleshtaker trigger, causing you to gain 1 life and scry 1.
4. Resolve the Mortuary trigger, putting Fanatical Firebrand from your graveyard onto the top of your library.
5. Resolve the Fanatical Firebrand ability.
6. Cast Fanatical Firebrand from the top of your library by paying 1 life.
7. Repeat.

This loop turns a humble goblin into an endless engine of destruction by turning your library into a revolving door. You use Fanatical Firebrand to ping an opponent, sending it to the graveyard where Mortuary immediately intercepts it to place it right back on top of your library. Meanwhile, Fleshtaker rewards your constant sacrifices with a steady stream of life and scry triggers to smooth the process. Tied together by Bolas's Citadel, which lets you bypass mana costs to recast the Fanatical Firebrand directly from the top of your library by paying a mere 1 life, you can effortlessly repeat the cycle until every opponent is reduced to ash.