Leonardo, Sewer Samurai + Solemnity + Thermopod + Ornithopter

Leonardo, Sewer Samurai

Solemnity

Thermopod

Ornithopter

How it works

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

This engine turns the humble Ornithopter into an endless cascade of sacrifice fodder, fueling Thermopod for infinite red mana by repeatedly looping the tiny flyer in and out of the graveyard. Leonardo, Sewer Samurai opens the gateway by letting you cast the 0-power Ornithopter straight from your graveyard during your turn. The true brilliance of the loop, however, relies on Solemnity; because it prevents counters from being put on permanents, Solemnity completely nullifies Leonardo's finality counter drawback, allowing the Ornithopter to enter the battlefield pristine and ready to be sacrificed over and over again.