Ashaya, Soul of the Wild, Rootpath Purifier, Murasa Rootgrazer, Retreat to Coralhelm, and Phyrexian Walker

Prerequisites

• Ashaya, Soul of the Wild on the battlefield
• Rootpath Purifier on the battlefield
• Murasa Rootgrazer on the battlefield
• Retreat to Coralhelm on the battlefield
• Phyrexian Walker on the battlefield

Steps

1. Activate Murasa Rootgrazer's second ability by tapping it, returning Phyrexian Walker to your hand from the battlefield
2. Cast Phyrexian Walker by paying
3. When Phyrexian Walker enters the battlefield, Retreat to Coralhelm triggers, untapping Murasa Rootgrazer
4. Repeat

Results

• Infinite ETB
• Infinite landfall triggers
• Infinite LTB
• Infinite storm count