Prototype Portal, Clock of Omens, Battered Golem, and Great Furnace

Prerequisites

• Prototype Portal on the battlefield
• Clock of Omens on the battlefield
• Battered Golem on the battlefield
• Great Furnace in exile

Steps

1. Activate Prototype Portal by paying , creating a token copy of Great Furnace
2. When the Great Furnace token enters the battlefield, Battered Golem triggers, untapping itself
3. Activate Clock of Omens by tapping Battered Golem and the Great Furnace token, untapping Prototype Portal
4. Repeat

Results

• Infinite landfall triggers
• Infinite tapped Great Furnace tokens