Grenzo, Dungeon Warden + The Cauldron of Eternity + Phyrexian Altar + Dark Ritual + Donnie & April, Adorkable Duo

Grenzo, Dungeon Warden

The Cauldron of Eternity

Phyrexian Altar

Dark Ritual

Donnie & April, Adorkable Duo

How it works

1. Cast Dark Ritual by paying , adding .
2. Activate Phyrexian Altar by sacrificing Donnie & April, adding one mana of any color.
3. When Donnie & April dies, The Cauldron of Eternity triggers, putting Donnie & April from your graveyard onto the bottom of your library.
4. Activate Grenzo by paying 2, putting Donnie & April from the bottom of your library into your graveyard, and then putting it onto the battlefield.
5. When Donnie & April 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 loop achieves infinite colored mana and an endless stream of triggers by tightly weaving together recursion and sacrifice. Dark Ritual funds the initial setup, while Phyrexian Altar converts Donnie & April, Adorkable Duo into the mana needed to keep the engine moving. The Cauldron of Eternity acts as the vital bridge that catches Donnie & April upon death, neatly shuttling it to the bottom of your library so Grenzo, Dungeon Warden can pluck it back out with his activated ability. Because Donnie & April's enter-the-battlefield trigger keeps pulling Dark Ritual back to your hand, you can recast the ritual, feed the Altar, and spin Grenzo over and over to unearth your entire creature collection.