Basalt Monolith + Donatello, Mutant Mechanic + Voltaic Construct

U identity

Commander legal

The 3 combo pieces

• Basalt Monolith
• Donatello, Mutant Mechanic
• Voltaic Construct

How to execute it

1. Animate Basalt Monolith using Donatello.
2. Activate Basalt Monolith by tapping it, adding {C}{C}{C}
3. Activate Voltaic Construct by paying {2}, untapping Basalt Monolith.
4. Repeat from step 2.

What the combo produces

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