Donna Noble, and Spitemare

Prerequisites

• Donna Noble on the battlefield
• Spitemare on the battlefield

Steps

1. Give Spitemare indestructible, if needed, and then deal damage to it
2. Donna Noble and Spitemare trigger
3. Resolve the Donna Noble trigger, dealing that much damage to an opponent
4. Resolve the Spitemare trigger, dealing that much damage to itself
5. Repeat from step 2

Results

• Infinite damage