Uyo, Silent Prophet, Retreat to Coralhelm, and Llanowar Scout

Prerequisites

• Uyo, Silent Prophet on the battlefield
• Retreat to Coralhelm on the battlefield
• Llanowar Scout on the battlefield
• plus enough mana to cast the instant or sorcery available

Steps

1. Cast any instant or sorcery by paying its mana cost
2. Holding priority, activate Uyo by paying and returning two lands you control from the battlefield to your hand, copying the instant or sorcery spell
3. Activate Llanowar Scout by tapping it, putting a land from your hand onto the battlefield
4. When the land enters the battlefield, Retreat to Coralhelm triggers, untapping Llanowar Scout Repeat steps 3 and 4 one additional time
5. Activate the lands by tapping them, adding at least
6. Repeat from step 2

Results

• Infinite magecraft triggers
• Infinite copies of instant and sorcery spells on the stack
• Infinite landfall