By turning every nonland permanent you control into an artifact with Encroaching Mycosynth, you open the door for Voltaic Construct to target non-traditional artifact creatures like Vhal, Candlekeep Researcher. With Vhal's hefty toughness generating plenty of colorless mana upon being tapped, you'll easily have enough energy to pay the Construct's activation cost and untap Vhal right back. This creates a self-sustaining loop that yields infinite untaps and infinite colorless mana for all your non-hand casting needs.