Fiendlash, Brash Taunter, and With Great Power...

Prerequisites

• Fiendlash on the battlefield
• Brash Taunter on the battlefield
• With Great Power
• on the battlefield

Steps

1. Deal damage to Brash Taunter
2. Brash Taunter and Fiendlash trigger
3. Resolve the Brash Taunter trigger, dealing damage to an applicable target
4. Resolve the Fiendlash trigger, targeting you, but dealing damage to Brash Taunter instead due to With Great Power
5. Repeat from step 2

Results

• Infinite damage to target opponent