Cloudstone Curio, Containment Construct, Dream Halls, Priest of Urabrask, and Teferi, Mage of Zhalfir

Prerequisites

• Cloudstone Curio on the battlefield
• Containment Construct on the battlefield
• Dream Halls on the battlefield
• Priest of Urabrask in hand
• Teferi, Mage of Zhalfir on the battlefield
• You have a nonartifact red creature card in hand with mana value two or less

Steps

1. Cast Priest of Urabrask by discarding another nonartifact red creature card with mana value two or less
2. Containment Construct triggers, causing you to exile the discarded card from your graveyard and allowing you to cast it this turn
3. Priest of Urabrask enters the battlefield, triggering itself and Cloudstone Curio
4. Resolve the Priest of Urabrask trigger, adding
5. Holding priority, cast the red creature from exile by paying its mana cost
6. The creature enters the battlefield, triggering Cloudstone Curio, returning Priest of Urabrask from the battlefield to your hand
7. Resolve the Cloudstone Curio trigger from step 3, returning the red creature to your hand
8. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite red mana
• Infinite storm count