Grenzo, Dungeon Warden + The Cauldron of Eternity + Phyrexian Altar + Dark Ritual + Mnemonic Wall

Grenzo, Dungeon Warden

The Cauldron of Eternity

Phyrexian Altar

Dark Ritual

Mnemonic Wall

How it works

1. Cast Dark Ritual by paying , adding .
2. Activate Phyrexian Altar by sacrificing Mnemonic Wall, adding one mana of any color.
3. When Mnemonic Wall dies, The Cauldron of Eternity triggers, putting Mnemonic Wall from your graveyard onto the bottom of your library.
4. Activate Grenzo by paying 2, putting Mnemonic Wall from the bottom of your library into your graveyard, and then putting it onto the battlefield.
5. When Mnemonic Wall 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 elegant loop relies on Grenzo, Dungeon Warden's ability to selectively pull creatures straight from the bottom of your library, a position maintained by The Cauldron of Eternity's passive ability that dutifully tucks your dying creatures back where Grenzo can find them. Once Mnemonic Wall is sacrificed to Phyrexian Altar for mana, its entry trigger returns Dark Ritual from the graveyard to hand, which then fuels both the altar's sacrifices and Grenzo's activation cost. The Cauldron of Eternity also pulls double duty here by making your creatures cheaper to cast if needed, completing a closed-loop engine that generates infinite colored mana and endless entry triggers.