Arni Metalbrow, Thousand-Faced Shadow, Cloudstone Curio, and Dockside Extortionist

Prerequisites

• Arni Metalbrow on the battlefield
• Thousand-Faced Shadow in hand
• Cloudstone Curio on the battlefield
• Dockside Extortionist on the battlefield
• Dockside Extortionist does not have summoning sickness
• Opponents control at least two artifacts and/or enchantments
• available

Steps

1. Declare Dockside Extortionist as an attacker
2. Arni Metalbrow triggers, causing you to pay to put Thousand-Faced Shadow from your hand onto the battlefield tapped and attacking
3. When Thousand-Faced Shadow enters the battlefield, it, Arni Metalbrow and Cloudstone Curio trigger
4. Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand from the battlefield
5. Resolve the Arni Metalbrow trigger, choosing not to pay
6. Resolve the Thousand-Faced Shadow trigger, creating a token copy of Dockside Extortionist that enters the battlefield tapped and attacking
7. When the Dockside Extortionist token enters the battlefield, it, Arni Metalbrow and Cloudstone Curio trigger
8. Resolve the Dockside Extortionist trigger, creating at least two Treasure tokens
9. Activate two Treasures by tapping and sacrificing them, adding
10. Resolve the Cloudstone Curio trigger, returning Thousand-Faced Shadow to your hand from the battlefield
11. Resolve the Arni Metalbrow trigger, causing you to pay to put Thousand-Faced Shadow from your hand onto the battlefield tapped and attacking
12. Repeat from step 3

Results

• Infinite colored mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count
• Infinite tapped creature tokens that are attacking
• Infinite Treasure tokens