Voltaic Construct, Karn, the Great Creator, and Gilded Lotus

Prerequisites

• Voltaic Construct on the battlefield
• Karn, the Great Creator on the battlefield
• Gilded Lotus on the battlefield

Steps

1. Animate Gilded Lotus using Karn, the Great Creator
2. Activate Gilded Lotus by tapping it, adding three mana of any color Activate Voltaic Construct by paying , untapping Gilded Lotus
3. Repeat from step 2

Results

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