Leonardo, Sewer Samurai + Solemnity + Goblin Bombardment + Shield Sphere

Leonardo, Sewer Samurai

Solemnity

Goblin Bombardment

Shield Sphere

How it works

1. Activate Goblin Bombardment by sacrificing Shield Sphere.
2. Cast Shield Sphere from your graveyard by paying 0. It will not enter with a finality counter on it due to Solemnity.
3. Repeat.

This clever loop uses Leonardo, Sewer Samurai to repeatedly cast Shield Sphere from your graveyard, enabled by its power or toughness of 1 or less and fueled by the safety net of Solemnity, which prevents finality counters from ever sticking to it. Once Shield Sphere hits the battlefield, you can instantly sacrifice it to Goblin Bombardment for a point of damage, triggering its leaves-the-battlefield and death effects all over again. Because Solemnity shuts down all counter placement, you never run out of fodder, letting you machine-gun the board with infinite damage and sacrifice triggers at zero mana cost.