Basalt Monolith, Tezzeret, Betrayer of Flesh, and Agatha of the Vile Cauldron

Prerequisites

• Basalt Monolith on the battlefield
• Tezzeret, Betrayer of Flesh on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Tezzeret has at least two loyalty counters on it
• Basalt Monolith does not have summoning sickness

Steps

1. Activate Tezzeret's second ability by removing two loyalty counters from it, causing Basalt Monolith to become an artifact creature
2. Activate Basalt Monolith's first ability by tapping it, adding
3. Activate Basalt Monolith's last ability by paying at most , untapping it
4. Repeat from step 2

Results

• Infinite colorless mana