Blazing Sunsteel, and Mirrormade

Prerequisites

• Blazing Sunsteel on the battlefield
• Mirrormade on the battlefield
• Blazing Sunsteel and Mirrormade attached to an indestructible creature you control
• You have a way to deal damage to the indestructible creature

Steps

1. Deal damage to the indestructible creature
2. Blazing Sunsteel and Mirrormade trigger
3. Resolve the Blazing Sunsteel trigger, dealing damage equal to the damage dealt to any target
4. Resolve the Mirrormade trigger, dealing damage equal to the damage dealt to the indestructible creature
5. Repeat from step 2

Results

• Infinite damage