Ertha Jo, Frontier Mentor, Clock of Omens, King Macar, the Gold-Cursed, and Encroaching Mycosynth

Prerequisites

• Ertha Jo, Frontier Mentor on the battlefield
• Clock of Omens on the battlefield
• King Macar, the Gold-Cursed on the battlefield
• Encroaching Mycosynth on the battlefield

Steps

1. Activate Clock of Omens by tapping it and King Macar, targeting King Macar
2. Ertha Jo triggers, copying Clock of Omens' ability, targeting Clock of Omens
3. Resolve both Clock of Omens abilities, untapping it and King Macar
4. King Macar triggers, exiling target creature and creating a Gold token
5. Repeat

Results

• Exile any number of target creatures
• Near-infinite Gold tokens