Mortuary + Goblin Bombardment + Bolas's Citadel + Shield Sphere

Mortuary

Goblin Bombardment

Bolas's Citadel

Shield Sphere

How it works

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

This clever loop turns zero-mana artifacts into a relentless engine of destruction, anchored by Bolas's Citadel allowing you to play cards directly from the top of your library by paying life instead of mana. You sacrifice Shield Sphere to Goblin Bombardment to deal damage, which naturally sends the tiny defender to the graveyard. Instantly, Mortuary intercepts that trip and places Shield Sphere right back on top of your library, perfectly positioned for Bolas's Citadel to let you recast it for free. Because Shield Sphere has a mana value of zero, you don't even lose any life to recast it, letting you repeat the cycle indefinitely to burn out the table.