Voltaic Construct + Karametra's Acolyte + Neurok Transmuter

Voltaic Construct

Karametra's Acolyte

Neurok Transmuter

How it works

1. Cause Karametra's Acolyte to become an artifact using Neurok Transmuter.
2. Activate Karametra's Acolyte by tapping it, adding at least .
3. Activate Voltaic Construct by paying 2, untapping Karametra's Acolyte.
4. Repeat from step 2.

By turning Karametra's Acolyte into an artifact using Neurok Transmuter's first ability, you cleverly set the stage for Voltaic Construct to interact with a mana dork that normally wouldn't be a valid target for its untap ability. Once the Acolyte is properly classified as an artifact creature, tapping it to generate a massive surge of green mana based on your devotion easily covers the two generic mana required by Voltaic Construct to untap it right back up. This creates a self-sustaining loop where the excess green mana fuels endless iterations, allowing you to generate infinite green mana and infinite untaps.