Basalt Monolith + March of the Machines + Training Grounds

Basalt Monolith

March of the Machines

Training Grounds

How it works

1. Activate Basalt Monolith's first ability by tapping it, adding CCC.
2. Activate Basalt Monolith's last ability by paying 1, untapping it.
3. Repeat.

This clever loop hinges on transforming a classic mana rock into a creature, allowing Training Grounds to fundamentally rewrite the math on Basalt Monolith's untap cost. Normally, untapping the Monolith costs three mana, which completely neutralizes the three colorless mana it produces; however, March of the Machines turns the Monolith into an artifact creature, letting the Grounds successfully slash that untap cost down to just a single mana. By cycling back and forth between tapping for three and untapping for one, you are left with a net gain of two colorless mana every single iteration, effortlessly generating an infinite supply of fuel for whatever massive spells you wish to cast.