Toph, the First Metalbender, and Caged Sun

Prerequisites

• Toph, the First Metalbender on the battlefield
• Caged Sun on the battlefield

Steps

1. Activate a land by tapping it, adding at least one mana of the color named by Caged Sun
2. Caged Sun triggers, adding one mana of that color
3. Caged Sun triggers again, as it is a land due to Toph, adding one mana of that color
4. Step 3 repeats in a mandatory infinite loop, causing the game to end in a draw

Results

• Draw the game