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

Prerequisites

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

Steps

1. Cast Priest of Gix by discarding another nonartifact black 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 Gix enters the battlefield, triggering itself and Cloudstone Curio
4. Resolve the Priest of Gix trigger, adding
5. Holding priority, cast the black creature from exile by paying its mana cost
6. The creature enters the battlefield, triggering Cloudstone Curio, returning Priest of Gix from the battlefield to your hand
7. Resolve the Cloudstone Curio trigger from step 3, returning the black creature to your hand
8. Repeat

Results

• Infinite black mana
• Infinite ETB
• Infinite LTB
• Infinite storm count