Voltaic Construct + Tough Cookie + Basalt Monolith

Voltaic Construct

Tough Cookie

Basalt Monolith

How it works

1. Animate Basalt Monolith using Tough Cookie.
2. Activate Basalt Monolith by tapping it, adding CCC.
3. Activate Voltaic Construct by paying 2, untapping Basalt Monolith.
4. Repeat from step 2.

This clever setup hinges on turning Basalt Monolith into an artifact creature using Tough Cookie's second ability, which makes it a valid target for Voltaic Construct. Once animated, tapping Basalt Monolith for three colorless mana provides more than enough energy to pay the two-mana cost required for Voltaic Construct to untap it, leaving you with a net profit of one colorless mana each cycle. You can repeat this loop indefinitely to generate infinite colorless mana, while also leaving Voltaic Construct and Tough Cookie primed for any additional artifact-based synergies you might need.