Basalt Monolith, Agatha of the Vile Cauldron, and Bello, Bard of the Brambles

Prerequisites

• Basalt Monolith on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Bello, Bard of the Brambles on the battlefield
• Agatha of the Vile Cauldron has power 1 or greater
• It is your turn

Steps

1. Activate Basalt Monolith's first ability by tapping it, adding
2. Activate Basalt Monolith's second ability by paying at most , untapping it
3. Repeat

Results

• Infinite colorless mana