Cogwork Assembler + Boommobile + Exalted Sunborn

Cogwork Assembler

Boommobile

Exalted Sunborn

How it works

1. Activate Cogwork Assembler by paying 7, creating two token copies of Boommobile.
2. When the Boommobile tokens enter the battlefield, they trigger, adding 8 that can only be spent to activate abilities.
3. Repeat.

This engine relies on Cogwork Assembler's expensive copy ability to turn Exalted Sunborn's token-doubling replacement effect into a massive windfall. By paying {7} to copy Boommobile, Exalted Sunborn ensures you get two entering Vehicles instead of one, which triggers both Boommobiles to flood your mana pool with eight mana specifically restricted to activating abilities. Since you only need seven of that mana to pay for Cogwork Assembler again, you are left with a net positive mana loop that infinitely duplicates your Boommobile tokens while fueling the exhaust ability for an infinite-damage sweep.