Dockside Extortionist + Cloudstone Curio

Prerequisites

You control a nontoken nonartifact creature. Opponents control a number of artifacts and/or enchantments equal to or greater than three plus the mana value of the additional nonartifact creature card.

Steps

1. Cast Dockside Extortionist by paying {1}{R}.
2. Dockside Extortionist enters the battlefield, triggering itself and Cloudstone Curio.
3. Resolve the Dockside Extortionist trigger, creating a number of Treasure tokens equal to the number of artifacts and/or enchantments your opponent control.
4. Resolve the Cloudstone Curio trigger, returning the additional nontoken nonartifact creature from the battlefield to your hand.
5. Activate a Treasure token by tapping and sacrificing it, adding one mana of any color.
6. Repeat step 5 until you have enough mana to cast the additional creature card.
7. Cast the additional creature by paying its mana cost.
8. The creature enters the battlefield, triggering Cloudstone Curio, returning Dockside Extortionist from the battlefield to your hand.
9. Activate two Treasure tokens by tapping and sacrificing them, adding {1}{R}.
10. Repeat.