Ensoul Artifact + Great Furnace + Prototype Portal + Retreat to Coralhelm

UR identity

Commander legal

The 4 combo pieces

What must be in place

Ensoul Artifact attached to Prototype Portal.
Prototype Portal does not have summoning sickness.

How to execute it

  1. Activate Prototype Portal by tapping it, creating a token copy of Great Furnace.
  2. When the Great Furnace token enters the battlefield, Retreat to Coralhelm triggers, untapping Prototype Portal.
  3. Repeat.

What the combo produces