Voltaic Construct, Karn, Silver Golem, and Empowered Autogenerator

Prerequisites

• Voltaic Construct on the battlefield
• Karn, Silver Golem on the battlefield
• Empowered Autogenerator on the battlefield
• available

Steps

1. Animate Empowered Autogenerator using Karn
2. Activate Empowered Autogenerator by tapping it, putting a charge counter on it and adding for each charge counter on it
3. Activate Voltaic Construct by paying , untapping Empowered Autogenerator
4. Repeat from step 2

Results

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