Basalt Monolith + Agatha of the Vile Cauldron + Trazyn the Infinite

Basalt Monolith

Agatha of the Vile Cauldron

Trazyn the Infinite

How it works

1. Activate Trazyn using Basalt Monolith's first ability by tapping it, adding CCC.
2. Activate Trazyn using Basalt Monolith's second ability by paying at most 2, untapping it.
3. Repeat

This engine turns your graveyard into a perpetual motion machine by pairing Trazyn the Infinite with Basalt Monolith in the graveyard, allowing Trazyn to absorb the artifact's tap and untap abilities. Normally, untapping Basalt Monolith costs three mana, but Agatha of the Vile Cauldron steps in with her passive cost reduction, shaving enough mana off the activation to let you untap Trazyn for just two mana. Because Trazyn generates three colorless mana with each tap and only needs two to untap, you net one colorless mana with every cycle, looping infinitely to generate boundless mana.