Dualcaster Mage, and Relm's Sketching

Prerequisites

• Dualcaster Mage in hand
• Relm's Sketching in hand
• available

Steps

1. Cast Relm's Sketching by paying its mana cost, targeting a creature you control
2. Holding priority, cast Dualcaster Mage by paying
3. When Dualcaster Mage enters the battlefield, it triggers, copying Relm's Sketching, targeting Dualcaster Mage
4. Resolve the copy of Relm's Sketching, creating a token copy of Dualcaster Mage
5. Repeat from step 3

Results

• Infinite ETB
• Infinite creature tokens
• Infinite magecraft triggers