Voltaic Construct, Karn, Silver Golem, and Gilded Lotus

Prerequisites

• Voltaic Construct on the battlefield
• Karn, Silver Golem on the battlefield
• Gilded Lotus on the battlefield
• available

Steps

1. Animate Gilded Lotus using Karn
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