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

Grenzo, Dungeon Warden

The Cauldron of Eternity

Phyrexian Altar

Dark Ritual

Skullwinder

How it works

1. Cast Dark Ritual by paying , adding .
2. Activate Phyrexian Altar by sacrificing Skullwinder, adding one mana of any color.
3. When Skullwinder dies, The Cauldron of Eternity triggers, putting Skullwinder from your graveyard onto the bottom of your library.
4. Activate Grenzo by paying 2, putting Skullwinder from the bottom of your library into your graveyard, and then putting it onto the battlefield.
5. When Skullwinder enters the battlefield, it triggers, returning Dark Ritual from your graveyard to your hand and causing an opponent to return a card to their hand from their graveyard.
6. Repeat.

This clever loop relies on Grenzo, Dungeon Warden to constantly pull Skullwinder straight from the bottom of your library whenever it is sent there. The Cauldron of Eternity plays a vital passive role here: whenever your creatures die, its static ability ensures they go directly to the bottom of your library where Grenzo can reach them, while its activated ability can also recycle graveyard threats. Phyrexian Altar turns Skullwinder into the necessary mana each cycle when sacrificed, and Dark Ritual provides the initial burst of black mana to set the whole engine in motion. As Skullwinder repeatedly enters and dies, its triggered ability constantly returns Dark Ritual back to your hand, allowing you to generate infinite colored mana and storm count while letting opponents empty their graveyards.