Leonardo, Sewer Samurai + Solemnity + Altar of Dementia + Shield Sphere

Leonardo, Sewer Samurai

Solemnity

Altar of Dementia

Shield Sphere

How it works

1. Activate Altar of Dementia 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 relies on Leonardo, Sewer Samurai to turn your graveyard into a second hand for tiny creatures, letting you recast Shield Sphere for free on your turn. While Leonardo would normally slap a finality counter on the Sphere to exile it upon death, Solemnity steps in to block all counters from ever being placed on your permanents. This lets you continuously feed Shield Sphere to Altar of Dementia to mill your opponents out completely, recycling the 0-mana defender endlessly without ever losing it to exile.