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

Prerequisites

• Uyo, Silent Prophet on the battlefield
• Walking Atlas on the battlefield
• Retreat to Coralhelm on the battlefield
• Any additional instant or sorcery card in hand
• You control two lands that enter the battlefield untapped and produce mana
• Walking Atlas does not have summoning sickness
• , plus enough mana to cast the instant or sorcery available

Steps

1. Cast any instant or sorcery by paying its mana cost
2. In response, activate Uyo by paying and returning two lands you control from the battlefield to your hand, copying an 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 Atlast
5. Repeat steps 3 and 4 one additional time
6. Activate those lands by tapping them, adding at least
7. Repeat from step 2 any number of times
8. Resolve any number of copies created in step 2 and the original spell

Results

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