Yarus, Roar of the Old Gods + Obscuring Aether + Earthcraft + Phyrexian Altar

Yarus, Roar of the Old Gods

Obscuring Aether

Earthcraft

Phyrexian Altar

How it works

1. Activate a basic land by tapping it, adding 1.
2. Activate Obscuring Aether by paying 1, turning it face-down as a 2/2 creature.
3. Activate Earthcraft by tapping Obscuring Aether, untapping the basic land.
4. Activate Phyrexian Altar by sacrificing Obscuring Aether, adding .
5. When Obscuring Aether dies, Yarus' second ability triggers, returning it from your graveyard to the battlefield face-down, then turning it face-up.
6. Repeat.

This clever loop transforms Obscuring Aether into a self-sacrificing engine by repeatedly morphing it into a creature and cashing it in. With Earthcraft allowing you to tap the newly minted 2/2 to untap a basic land for mana, and Phyrexian Altar providing the final sacrifice outlet to generate the required green mana, the loop becomes fully self-sustaining. Every time the enchantment hits the graveyard, Yarus, Roar of the Old Gods steps in with its recursion ability to return it to the battlefield face down and immediately flip it back face up, restarting the entire cycle.