Mortuary + Goblin Bombardment + Shield Sphere + Gwenom, Remorseless

Mortuary

Goblin Bombardment

Shield Sphere

Gwenom, Remorseless

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 delightfully grim engine lets you recycle a single artifact creature indefinitely to blast away your opponents. It all starts with Goblin Bombardment, which provides the sacrifice outlet to clear away Shield Sphere and deal a point of damage. Because Shield Sphere costs zero mana to cast, it serves as the ultimate fuel, returning straight to the top of your library thanks to Mortuary's triggered ability every time it hits the graveyard. Finally, Gwenom, Remorseless ties the whole loop together by granting you the ability to play cards directly from the top of your library, letting you recast the free-to-cast Shield Sphere over and over again without ever needing actual mana.