Mortuary + Zulaport Cutthroat + Fanatical Firebrand + Gwenom, Remorseless

Mortuary

Zulaport Cutthroat

Fanatical Firebrand

Gwenom, Remorseless

How it works

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

This loop sets up an efficient little recursion engine using Fanatical Firebrand as its looping piece, letting you repeatedly tap and sacrifice it for damage. Whenever it hits the graveyard, Mortuary intercepts it to place the goblin right back on top of your library. From there, Gwenom, Remorseless lets you bypass normal casting costs by playing it straight off the top of your library while paying life instead, a cost easily offset by Zulaport Cutthroat draining your opponents and padding your life total with every single iteration.