King Macar, the Gold-Cursed, Karn, Silver Golem, Clock of Omens, and Mycosynth Lattice

Prerequisites

• King Macar, the Gold-Cursed on the battlefield
• Karn, Silver Golem on the battlefield
• Clock of Omens on the battlefield
• Mycosynth Lattice on the battlefield
• One of your opponents controls a creature

Steps

1. Activate Clock of Omens by tapping itself and King Macar, untapping King Macar
2. King Macar triggers, exiling any creature an opponent controls and creating a Gold token
3. Activate Clock of Omens by tapping the Gold token and King Macar, targeting King Macar
4. Holding priority, activate the Gold token by sacrificing it, adding
5. Activate Karn by paying , causing target noncreature permanent an opponent controls to become an artifact creature until end of turn
6. Resolve the Clock of Omens ability, untapping King Macar
7. Repeat from step 2

Results

• Exile all nonland permanents your opponents control