Prosper, Tome-Bound, Portcullis, Eternal Scourge, and Planar Gate

Prerequisites

• Prosper, Tome-Bound on the battlefield
• Portcullis on the battlefield
• Eternal Scourge in hand or in exile
• Planar Gate on the battlefield
• plus an additional available if Eternal Scourge is in hand available

Steps

1. Cast Eternal Scourge either from your hand or from exile by paying
2. If you played Eternal Scourge from exile, Prosper's second ability triggers, creating a Treasure token
3. Eternal Scourge enters the battlefield, triggering Portcullis, exiling Eternal Scourge
4. If you created a Treasure token, activate it by tapping and sacrificing it, adding
5. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite storm count