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

Prerequisites

• Grenzo, Dungeon Warden on the battlefield
• The Cauldron of Eternity on the battlefield
• Phyrexian Altar on the battlefield
• Dark Ritual in hand
• Skullwinder on the battlefield
• Grenzo has power 2 or greater
• available

Steps

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 , 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

Results

• Infinite LTB
• Infinite ETB
• Infinite colored mana
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite storm count
• Infinite magecraft triggers
• Put all creature cards with power less than or equal to Grenzo's from your library onto the battlefield
• Target opponent returns all cards in their graveyard to their hand