Myrkul, Lord of Bones, Ondu Spiritdancer, and Grim Guardian

Prerequisites

• Myrkul, Lord of Bones on the battlefield
• Ondu Spiritdancer on the battlefield
• Grim Guardian on the battlefield
• You have a way to kill Ondu Spiritdancer

Steps

1. Kill Ondu Spiritdancer
2. Myrkul triggers, creating a token copy of Ondu Spiritdancer that is an enchantment
3. When the token Ondu Spiridancer enters the battlefield, it and Grim Guardian trigger
4. Resolve the Grim Guardian trigger, causing each opponent to lose 1 life
5. Resolve the Ondu Spiritdancer trigger, creating a token copy of itself
6. Repeat from step 3

Results

• Infinite lifeloss
• Infinite Ondu Spiritdancer tokens that are enchantments