Grenzo, Dungeon Warden + The Cauldron of Eternity + Phyrexian Altar + Dark Ritual + Zealous Lorecaster

Grenzo, Dungeon Warden

The Cauldron of Eternity

Phyrexian Altar

Dark Ritual

Zealous Lorecaster

How it works

1. Cast Dark Ritual by paying , adding .
2. Activate Phyrexian Altar by sacrificing Zealous Lorecaster, adding one mana of any color.
3. When Zealous Lorecaster dies, The Cauldron of Eternity triggers, putting Zealous Lorecaster from your graveyard onto the bottom of your library.
4. Activate Grenzo by paying 2, putting Zealous Lorecaster from the bottom of your library into your graveyard, and then putting it onto the battlefield.
5. When Zealous Lorecaster enters the battlefield, it triggers, returning Dark Ritual from your graveyard to your hand.
6. Repeat.
7. Once you have infinite mana, you may activate Grenzo's ability any number of times.

This clever loop uses Grenzo, Dungeon Warden as a recursive engine to repeatedly cheat out Zealous Lorecaster, whose enters-the-battlefield ability continually recycles Dark Ritual back to your hand for infinite mana. Phyrexian Altar acts as the sacrifice outlet that both fuels your color requirements and feeds creatures straight into the graveyard, where The Cauldron of Eternity steps in with its passive ability to seamlessly route every dying creature right back to the bottom of your library. Because Grenzo's ability looks specifically at the bottom of your library, The Cauldron of Eternity's replacement effect ensures your fodder is always precisely where Grenzo needs it to repeat the cycle indefinitely.