Idris, Soul of the TARDIS + Grim Monolith + Biomancer's Familiar

Idris, Soul of the TARDIS

Grim Monolith

Biomancer's Familiar

How it works

1. Activate Idris using Grim Monolith's first ability by tapping it, adding CCC.
2. Activate Idris using Grim Monolith's second ability by paying 2, untapping it.
3. Repeat.

This potent loop begins by using Idris, Soul of the TARDIS to imprint Grim Monolith when Idris enters the battlefield, granting Idris the artifact's mana-producing and untapping abilities. Normally, untapping Grim Monolith would cost a prohibitive four mana, but Biomancer's Familiar steps in as a crucial cost-reducer, dropping the untap activation cost down to just two mana. Because the Monolith generates three colorless mana while the discounted untap costs only two, you net one colorless mana each cycle, creating an infinite reservoir of mana to fuel the rest of your game plan.