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

Prerequisites

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

Steps

1. Animate Nyx Lotus using Karn, the Great Creator
2. Activate Nyx Lotus by tapping it, adding at least Activate Voltaic Construct by paying , untapping Nyx Lotus
3. Repeat from step 2

Results

• Infinite untap of artifact creatures you control
• Infinite mana of colors you have devotion to