Molten Echoes, and Lightning Crafter

Prerequisites

• Molten Echoes on the battlefield
• Lightning Crafter on the battlefield
• undefined

Steps

1. Cast Lightning Crafter by paying its mana cost
2. When Lightning Crafter enters the battlefield, its champion ability and Molten Echoes triggers
3. Resolve the Molten Echoes trigger, creating a token copy of Lightning Crafter with haste
4. When the Lightning Crafter token enters the battlefiled, its champion ability triggers, exiling the nontoken Lightning Crafter until the token Lightning Crafter leaves the battlefield
5. Holding priority, activate the Lightning Crafter token by tapping it, dealing 3 damage to any target
6. Resolve the champion ability from step 2, exiling the token Lightning Crafter
7. The token Lightning Crafter leaves the battlefield, returning the nontoken Lightning Crafter from exile to the battlefield
8. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB
• Infinite damage