Boommobile, Emiel the Blessed, and Steelfin Whale

Prerequisites

• Boommobile on the battlefield
• Emiel the Blessed on the battlefield
• Steelfin Whale on the battlefield

Steps

1. Activate Boommobile's crew ability by tapping Steelfin Whale, causing Boommobile to become an artifact creature until end of turn
2. Activate Emiel by paying , blinking Boommobile
3. When Boommobile enters the battlefield, it and Steelfin Whale trigger
4. Resolve the Steelfin Whale trigger, untapping it
5. Resolve the Boommobile trigger, adding four mana of any color that can only be spent to activate abilities
6. Repeat

Results

• Infinite artifact ETB
• Infinite artifact LTB
• Infinite creature LTB
• Infinite damage
• Infinite colored mana that can only be spent to activate abilities