Voltaic Construct, Karn, the Great Creator, and Prismatic Geoscope

Prerequisites

• Voltaic Construct on the battlefield
• Karn, the Great Creator on the battlefield
• Prismatic Geoscope on the battlefield

Steps

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

Results

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