Leonardo, Sewer Samurai + Solemnity + Umbral Collar Zealot + Phyrexian Walker

Leonardo, Sewer Samurai

Solemnity

Umbral Collar Zealot

Phyrexian Walker

How it works

1. Activate Umbral Collar Zealot 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 ingenious loop turns a modest artifact creature into an endless engine of sacrifice and graveyard recursion. By having Solemnity on the battlefield, you neatly bypass Leonardo, Sewer Samurai's drawback of placing finality counters on creatures cast from the graveyard, allowing Phyrexian Walker to be recast over and over for free. Each iteration feeds Umbral Collar Zealot's ability by sacrificing Phyrexian Walker to surveil through your library, generating infinite entry, death, and sacrifice triggers along the way.