Mortuary + Goblin Bombardment + Bolas's Citadel + Serrated Scorpion

Mortuary

Goblin Bombardment

Bolas's Citadel

Serrated Scorpion

How it works

1. Activate Goblin Bombardment by sacrificing Serrated Scorpion.
2. When Serrated Scorpion dies, it and Mortuary triggers.
3. Resolve the Mortuary trigger, putting Serrated Scorpion from your graveyard onto the top of your library.
4. Resolve the Serrated Scorpion trigger, causing you to gain 2 life and dealing 2 damage to each opponent.
5. Resolve the Goblin Bombardment ability.
6. Cast Serrated Scorpion from the top of your library by paying 1 life due to Bolas's Citadel.
7. Repeat.

This loop turns a simple sacrifice into a devastating engine of attrition by turning your library into a revolving door for your creatures. You sacrifice Serrated Scorpion to Goblin Bombardment, which triggers the Scorpion's own death ability alongside Mortuary to immediately stack the creature right back onto the top of your library. From there, Bolas's Citadel steps in to bypass mana costs entirely, letting you replay the Scorpion using your life total instead—a cost effortlessly offset by the life you gain from the Scorpion's death trigger.