Dualcaster Mage, Riptide Laboratory, and Turnabout

Prerequisites

• Dualcaster Mage in hand
• Riptide Laboratory on the battlefield
• Turnabout in hand
• Other lands that can produce on the battlefield
• available

Steps

1. Cast Turnabout by paying , targeting any land you control
2. Holding priority, cast Dualcaster Mage by paying
3. Dualcaster Mage enters the battlefield, copying Turnabout
4. Holding priority, activate Riptide Laboratory by paying and tapping it, returning Dualcaster Mage to your hand
5. Resolve the Turnabout copy, untapping all lands you control
6. Repeat from step 2

Results

• Infinite colored mana
• Infinite ETB
• Infinite LTB
• Infinite storm count