Leonardo, Sewer Samurai + Tatterkite + Krark-Clan Ironworks + Gathering Stone

Leonardo, Sewer Samurai

Tatterkite

Krark-Clan Ironworks

Gathering Stone

How it works

1. Cast Tatterkite from your graveyard by paying 2 due to Gathering Stone. It won't enter with a finality counter on it due to its static ability.
2. Activate Krark-Clan Ironworks by sacrificing Tatterkite, adding CC
3. Repeat.

This brilliant recursive loop hinges on Leonardo, Sewer Samurai, whose static ability allows you to repeatedly cast Tatterkite right out of your graveyard. Normally, casting it this way would saddle it with a finality counter, but Tatterkite's own built-in protection completely ignores that restriction and enters the battlefield clean. Meanwhile, Gathering Stone quietly reduces the casting cost so the loop remains mana-neutral, and Krark-Clan Ironworks sacrifices the artifact to supply the exact color-free mana needed to start it all over again.