Leonardo, Sewer Samurai + Solemnity + Umbral Collar Zealot + Kobolds of Kher Keep

Leonardo, Sewer Samurai

Solemnity

Umbral Collar Zealot

Kobolds of Kher Keep

How it works

1. Activate Umbral Collar Zealot by sacrificing Kobolds of Kher Keep.
2. Cast Kobolds of Kher Keep from your graveyard by paying 0. It will not enter with a finality counter on it due to Solemnity.
3. Repeat.

This brilliant little engine transforms free resources into an endless loop by leveraging Leonardo, Sewer Samurai's ability to let you cast 1-power or 1-toughness creatures directly from your graveyard. Because Kobolds of Kher Keep costs zero mana to cast, you can immediately sacrifice it to Umbral Collar Zealot's ability to surveil your deck and feed your graveyard. The true magic, however, relies on Solemnity; its static replacement effect prevents counters from ever being put on your permanents, bypassing the finality counter that Leonardo would normally place on the recurring Kobolds. Together, these pieces bypass the graveyard exile restriction entirely, generating an endless cascade of sacrifice, enter-the-battlefield, and leave-the-battlefield triggers.