Voltaic Construct, The Blackstaff of Waterdeep, and Grim Monolith

Prerequisites

• Voltaic Construct on the battlefield
• The Blackstaff of Waterdeep on the battlefield
• Grim Monolith on the battlefield
• available

Steps

1. Animate Grim Monolith using The Blackstaff of Waterdeep
2. Activate Grim Monolith by tapping it, adding
3. Activate Voltaic Construct by paying , untapping Grim Monolith
4. Repeat from step 2

Results

• Infinite colorless mana
• Infinite untap of artifact creatures you control