Idris, Soul of the TARDIS + Lithoform Engine + Basalt Monolith + Sphinx's Disciple + Encroaching Mycosynth

Idris, Soul of the TARDIS

Lithoform Engine

Basalt Monolith

Sphinx's Disciple

Encroaching Mycosynth

How it works

1. Cast Idris either from your hand or from the command zone by paying 1 and commander tax, if applicable.
2. When Idris enters the battlefield, its imprint ability triggers, targeting Sphinx's Disciple.
3. Holding priority, activate Lithoform Engine's first ability by paying 2 and tapping it, copying Idris' trigger, targeting Basalt Monolith.
4. Resolve both Idris triggers, exiling Basalt Monolith and Sphinx's Disciple.
5. During your next turn, activate Idris using Basalt Monolith's first ability by tapping it, adding CCC.
6. Activate Idris using Basalt Monolith's second ability by paying 3, untapping it.
7. Sphinx's Disciple triggers, causing you to draw a card.
8. Repeat from step 5.

This ingenious loop turns Idris, Soul of the TARDIS into a relentless engine by leveraging Lithoform Engine to double its imprint trigger so it can consume both Basalt Monolith and Sphinx's Disciple simultaneously. Encroaching Mycosynth quietly lays the groundwork by ensuring everything on your board is treated as an artifact, while Basalt Monolith provides the engine's infinite mana loop via its ability to tap for three colorless and untap for three. Because Idris inherits the activated and triggered abilities of everything it has exiled, the untapping process simultaneously sparks Sphinx's Disciple's inspired ability to fuel infinite card draw.