Smaug the Impenetrable + Metalwork Colossus + Parallel Lives + Goblin Bombardment

Smaug the Impenetrable

Metalwork Colossus

Parallel Lives

Goblin Bombardment

How it works

1. Activate Goblin Bombardment by sacrificing Metalwork Colossus, dealing 1 damage to Smaug.
2. Smaug triggers, creating two artifact tokens due to Parallel Lives.
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. Repeat.

This delightful loop turns the dragon's hoard against itself, using Goblin Bombardment to deal noncombat damage to Smaug the Impenetrable. That damage triggers Smaug's ability to create Treasure tokens, which are instantly doubled by Parallel Lives to feed the Bombardment's sacrifice costs. Meanwhile, the massive mana value of those artifacts allows you to cast Metalwork Colossus for free, and its ability to sacrifice those very same treasures from your graveyard ensures the cycle can repeat indefinitely.