Teferi, Temporal Archmage + Lithoform Engine

Teferi, Temporal Archmage

Lithoform Engine

How it works

1. Activate Teferi, Temporal Archmage's second ability by removing a loyalty counter from it.
2. In response, activate Lithoform Engine's first ability by paying 2 and tapping it, copying Teferi's activated ability.
3. Let the copied ability resolve, untapping three lands and Lithoform Engine.
4. Activate those lands by tapping them, adding at least 3.
5. Repeat from step 2.
6. Once you have infinite mana, you may untap any permanents in step 3.

This elegant loop turns Teferi, Temporal Archmage into an engine of endless power by capitalizing on Lithoform Engine's ability to duplicate activated triggers. By targeting Teferi's minus ability with the artifact's copy effect, you generate enough untap triggers to repeatedly refresh your mana sources, including Lithoform Engine itself. Because the copied ability resolves first, you untap your lands and the copying artifact before the original ability even needs to finish, leaving you with infinite mana and any other permanent you control completely untapped.