Clock of Omens + Great Furnace + Grinding Station + Prototype Portal

R identity

Commander legal

The 4 combo pieces

How to execute it

  1. Activate Prototype Portal by paying {0} and tapping it, creating a token copy of Great Furnace.
  2. The Great Furnace token enters, triggering Grinding Station, untapping Grinding Station.
  3. Activate Clock of Omens by tapping the Great Furnace token and Grinding Station, untapping Prototype Portal.
  4. Repeat.

What the combo produces