Voltaic Construct + Ashnod's Transmogrant + Selvala, Eager Trailblazer

Voltaic Construct

Ashnod's Transmogrant

Selvala, Eager Trailblazer

How it works

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

This clever setup turns Selvala, Eager Trailblazer into an artifact creature with the help of Ashnod's Transmogrant, allowing her to be targeted by Voltaic Construct's untap ability. Once Selvala is an artifact, her tap ability generates enough mana to pay for the Construct's activation cost and leave some leftover profit. By looping this sequence, you can generate infinite colored mana to fuel any further plays your deck desires.