Riku of Two Reflections, and Worldgorger Dragon

Prerequisites

• Riku of Two Reflections on the battlefield
• Worldgorger Dragon in hand
• You control any number of permanents that enter the battlefield untapped and can tap to produce at least
• available

Steps

1. Cast Worldgorger Dragon by paying
2. Worldgorger Dragon enters the battlefield, triggering its first ability and Riku's second ability
3. Holding priority, activate any number of permanents by tapping them, adding at least
4. Resolve the Riku trigger, causing you to pay to create a token copy of Worldgorger Dragon
5. The token Worldgorger Dragon enters the battlefield, triggering its first ability, exiling all other permanents you control
6. The nontoken Worldgorger Dragon leaves the battlefield, triggering its second ability, returning nothing from exile to the battlefield
7. Resolve the Worldgorger Dragon trigger from step 2, exiling the token Worldgorger Dragon
8. The token Worldgorger Dragon leaves the battlefield, triggering its second ability, returning all permanents exiled with it to the battlefield
9. Repeat from step 2

Results

• Infinite blinking of permanents you control
• Infinite ETB
• Infinite LTB
• Infinite mana permanents you control can produce