Basalt Monolith, The Blackstaff of Waterdeep, and Agatha of the Vile Cauldron

Prerequisites

• Basalt Monolith on the battlefield
• The Blackstaff of Waterdeep on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Basalt Monolith does not have summoning sickness
• available

Steps

1. Activate The Blackstaff of Waterdeep by paying and tapping 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