Coveted Jewel + Donatello, Mutant Mechanic + Voltaic Construct

U identity

Commander legal

The 3 combo pieces

• Coveted Jewel
• Donatello, Mutant Mechanic
• Voltaic Construct

How to execute it

1. Animate Coveted Jewel using Donatello.
2. Activate Coveted Jewel by tapping it, adding three mana of any color
3. Activate Voltaic Construct by paying {2}, untapping Coveted Jewel.
4. Repeat from step 2.

What the combo produces

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