Dualcaster Mage, and Cackling Counterpart

Prerequisites

• Dualcaster Mage in hand
• Cackling Counterpart in hand
• You control at least one creature
• You have enough mana to cast Cackling Counterpart available

Steps

1. Cast Cackling Counterpart 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 Cackling Counterpart, targeting Dualcaster Mage
4. Resolve the copy of Cackling Counterpart, creating a token copy of Dualcaster Mage
5. Repeat from step 3

Results

• Infinite ETB
• Infinite creature tokens
• Infinite magecraft triggers