Smaug the Impenetrable + Metalwork Colossus + Blasting Station + Peregrin Took

Smaug the Impenetrable

Metalwork Colossus

Blasting Station

Peregrin Took

How it works

1. Activate Blasting Station by tapping it and sacrificing Metalwork Colossus, dealing 1 damage to Smaug.
2. Smaug triggers, creating two artifact tokens due to Peregrin Took.
3. Activate Metalwork Colossus by sacrificing the two artifact tokens, returning Metalwork Colossus from your graveyard to your hand.
4. Cast Metalwork Colossus by paying 0.
5. When Metalwork Colossus enters, Blasting Station triggers, untapping Blasting Station.
6. Repeat.

This loop relies on a brilliant feedback loop centered around Smaug the Impenetrable, whose indestructible nature lets it happily take 1 noncombat damage from Blasting Station to trigger its treasure generation. Peregrin Took ensures that whenever those tokens are created, an additional Food token is added to the mix, fueling the exact artifact count needed. Meanwhile, Metalwork Colossus drops its casting cost to zero thanks to the noncreature artifacts you control, allowing it to be recast immediately after its sacrifice. Every time Metalwork Colossus enters the battlefield, Blasting Station untaps itself to repeat the cycle endlessly.