Altar of Souls (yes)
SO MUCH SYNERGY.
While this deck isn't the first version of this archetype to appear on the 'Hub, I think it is one of the leanest. With a good draw you can get going pretty fast. Though it's no aggro deck of course.
The win condition is Mistral Guide plus a never ending stream of Shadows, once the engine gets going.
I'm not 100% settled on the Roaming Yak. Being able to put down prairies helps speed up early land placement, as one of the early challenges is getting enough space to put down all your structures while still having open deserts to put down Shadows in the right locations. Consider swapping it out for Queens Guard or something else, IDK.