Guilty Conscience, and Boros Reckoner

Prerequisites

• Guilty Conscience on the battlefield
• Boros Reckoner on the battlefield

Steps

1. Cause Boros Reckoner to take damage by any method
2. Boros Reckoner triggers, dealing damage to an opponent
3. Guilty Conscience triggers, dealing damage to Boros Reckoner
4. Repeat from step 2

Results

• Infinite damage