The Red Terror, and Shalai and Hallar

Prerequisites

• The Red Terror on the battlefield
• Shalai and Hallar on the battlefield

Steps

1. Any opponent takes damage
2. The The Red Terror triggers, putting a counter on a permanent
3. All Shalai and Hallar triggers, dealing at least 1 damage to an opponent
4. Repeat from step 2

Results

• Infinite damage