Leonardo, Sewer Samurai + Tatterkite + Phyrexian Altar + Ezzaroot Channeler

Leonardo, Sewer Samurai

Tatterkite

Phyrexian Altar

Ezzaroot Channeler

How it works

1. Cast Tatterkite from your graveyard by paying at most 1 due to Ezzaroot Channeler. It won't enter with a finality counter on it due to its static ability.
2. Activate Phyrexian Altar by sacrificing Tatterkite.
3. Repeat.

This crafty loop hinges on Leonardo, Sewer Samurai's ability to repeatedly pluck cheap threats straight from the graveyard during your turn. Tatterkite is the perfect recurring engine for this, as its built-in static ability blocks finality counters from ever landing on it, letting it bypass exile and enter the graveyard cleanly every time. Meanwhile, Ezzaroot Channeler's passive cost reduction makes casting Tatterkite virtually free, offsetting its mana value completely. Finally, sacrificing the insect to Phyrexian Altar generates the colored mana needed to fuel the whole cycle while instantly setting up your next recursion loop.