Basalt Monolith, Workshop Elders, and Agatha of the Vile Cauldron

Prerequisites

• Basalt Monolith on the battlefield
• Workshop Elders on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Basalt Monolith does not have summoning sickness
• Agatha of the Vile Cauldron has power 1 or greater

Steps

1. At the beginning of your combat phase, Workshop Elders triggers, causing Basalt Monolith to become a 0/0 artifact creature, then putting four +1/+1 counters on it
2. Activate Basalt Monolith's first ability by tapping it, adding
3. activate Basalt Monolith's second ability by paying at most , untapping it
4. Repeat from step 2

Results

• Infinite colorless mana