Voltaic Construct + Sydri, Galvanic Genius + Prismatic Geoscope

Voltaic Construct

Sydri, Galvanic Genius

Prismatic Geoscope

How it works

1. Animate Prismatic Geoscope using Sydri.
2. Activate Prismatic Geoscope by tapping it, adding at least three mana of any color
3. Activate Voltaic Construct by paying 2, untapping Prismatic Geoscope.
4. Repeat from step 2.

This clever loop turns your mana rocks into a self-sustaining engine by relying on Sydri, Galvanic Genius to temporarily turn Prismatic Geoscope into an artifact creature. Once it's a creature, tapping Prismatic Geoscope yields enough domain-fueled colored mana to easily fund the {2} activation cost of Voltaic Construct. The construct then untaps the Geoscope, leaving you with a net surplus of mana and ready to repeat the process for infinite colored mana.