Uyo, Silent Prophet, Retreat to Coralhelm, and Walking Atlas

Prerequisites

• Uyo, Silent Prophet on the battlefield
• Retreat to Coralhelm on the battlefield
• Walking Atlas 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 Walking Atlas by tapping it, putting a land from your hand onto the battlefield
4. When the land enters the battlefield, Retreat to Coralhelm triggers, untapping Walking Atlas 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 copies of instant and sorcery spells on the stack
• Infinite landfall
• Infinite magecraft triggers