Blazing Sunsteel, and Donna Noble

Prerequisites

• Blazing Sunsteel on the battlefield
• Donna Noble on the battlefield

Steps

1. Deal damage to Donna Noble or the creature it is paired with
2. Donna Noble and Blazing Sunsteel trigger
3. Resolve the Donna Noble trigger, dealing damage to an opponent
4. Resolve the Blazing Sunsteel trigger, dealing damage to the creature it is attached to Repeat from step 2

Results

• Infinite damage