Leonardo, Sewer Samurai + Solemnity + Ashnod's Altar + Phyrexian Walker

Leonardo, Sewer Samurai

Solemnity

Ashnod's Altar

Phyrexian Walker

How it works

1. Activate Ashnod's Altar by sacrificing Phyrexian Walker.
2. Cast Phyrexian Walker from your graveyard by paying 0. It will not enter with a finality counter on it due to Solemnity.
3. Repeat.

This clever loop turns the graveyard into an endless engine by leveraging Leonardo, Sewer Samurai's ability to recur cheap threats during your turn. The true brilliance here lies in Solemnity, which brilliantly prevents Leonardo's finality counters from ever touching your permanents, allowing the same creature to return endlessly without being exiled upon death. You feed this loop with Phyrexian Walker—a free spell that costs nothing to cast from the graveyard—which you then immediately sacrifice to Ashnod's Altar to generate a surplus of colorless mana alongside infinite triggers.