Darksteel Citadel + Goblin Welder + Great Furnace + Retreat to Coralhelm

UR identity

Commander legal

The 4 combo pieces

What must be in place

Goblin Welder does not have summoning sickness.

How to execute it

  1. Activate Goblin Welder by tapping it, causing you to sacrifice Great Furnace and return Darksteel Citadel from your graveyard to the battlefield.
  2. Darksteel Citadel enters the battlefield, triggering Retreat to Coralhelm, untapping Goblin Welder.
  3. Activate Darksteel Citadel by tapping it, adding {C}.
  4. Activate Goblin Welder by tapping it, causing you to sacrifice Darksteel Citadel and return Great Furnace from your graveyard to the battlefield.
  5. Great Furnace enters the battlefield, triggering Retreat to Coralhelm, untapping Goblin Welder.
  6. Activate Great Furnace by tapping it, adding {R}.
  7. Repeat.

What the combo produces