Voltaic Construct + Karn, the Great Creator + The Eternity Elevator

Voltaic Construct

Karn, the Great Creator

The Eternity Elevator

How it works

1. Animate The Eternity Elevator using Karn, the Great Creator.
2. Activate The Eternity Elevator by tapping it, adding CCC.
3. Activate Voltaic Construct by paying 2, untapping The Eternity Elevator.
4. Repeat from step 2.

This clever loop transforms The Eternity Elevator into an explosive engine by using Karn, the Great Creator's first ability to turn it into an artifact creature. Once animated, tapping The Eternity Elevator yields three colorless mana, which easily covers the activation cost for Voltaic Construct to untap it right back. Repeating this process creates an infinite surplus of colorless mana, which can then be funneled into The Eternity Elevator's massive station-ability mana production once you hit twenty charge counters to generate infinite mana of any color.