Mortuary + Shilgengar, Sire of Famine + Crimson Kobolds + Gwenom, Remorseless

Mortuary

Shilgengar, Sire of Famine

Crimson Kobolds

Gwenom, Remorseless

How it works

1. Activate Shilgengar by sacrificing Crimson Kobolds
2. When Crimson Kobolds dies, Mortuary triggers, putting Crimson Kobolds from your graveyard onto the top of your library.
3. Resolve the Shilgengar ability.
4. Cast Crimson Kobolds from the top of your library by paying 0 life.
5. Repeat.

This brilliant loop turns Shilgengar, Sire of Famine into a relentless sacrifice engine by using Mortuary to instantly recycle whatever falls to his blade right back onto your library. While Crimson Kobolds provides a zero-mana creature that can be repeatedly sacrificed and recast for free, Gwenom, Remorseless capitalizes on the action by letting you play that creature directly off the top of your library (though you'll want to mind your life total when casting non-zero spells this way). Each iteration generates an endless stream of Blood tokens and triggers, ultimately feeding back into Shilgengar's massive graveyard-recursion ability to overwhelm the board.