Thopter Foundry + Metalwork Colossus + Pitiless Plunderer

Thopter Foundry

Metalwork Colossus

Pitiless Plunderer

How it works

1. Cast Metalwork Colossus by paying 0.
2. Activate Thopter Foundry by paying 1 and sacrificing Metalwork Colossus.
3. When Metalwork Colossus dies, Pitiless Plunderer triggers, creating a Treasure token.
4. Resolve the Thopter Foundry trigger, creating a 1/1 Thopter artifact creature token and causing you to gain 1 life.
5. Activate Metalwork Colossus by sacrificing the Thopter and Treasure.
6. When the Thopter dies, Pitiless Plunderer triggers, creating a Treasure token.
7. Resolve the Metalwork Colossus ability, returning it from your graveyard to your hand.
8. Activate the Treasure by tapping and sacrificing it, adding 1.
9. Repeat.