Guilty Conscience, Truefire Captain, and Indestructibility

Prerequisites

• Guilty Conscience on the battlefield
• Truefire Captain on the battlefield
• Indestructibility on the battlefield
• Indestructibility and Guilty Conscience attached to Truefire Captain
• Truefire Captain does not have summoning sickness

Steps

1. Attack with Truefire Captain
2. When Truefire Captain deals damage, Guilty Conscience triggers, dealing damage to Truefire Captain equal to the amount of damage Truefire Captain dealt
3. Truefire Captain triggers, dealing damage equal to the amount of damage Guilty Conscience dealt to it to any target
4. Repeat from step 2

Results

• Infinite damage