Toph, the First Metalbender, Blossoming Tortoise, and Basalt Monolith

Prerequisites

• Toph, the First Metalbender on the battlefield
• Blossoming Tortoise on the battlefield
• Basalt Monolith on the battlefield

Steps

1. Activate Basalt Monolith's first ability by tapping it, adding
2. Activate Basalt Monolith's second ability by paying , as its cost is reduced by Blossoming Tortoise, due to being a land because of Toph, untapping Basalt Monolith
3. Repeat

Results

• Infinite colorless mana