If you love strange, queer witchcraft plots told at a slant, gorgeous tight descriptions of the American Midwest and mountain states, mirage-like non-linear plots, and Sam's hand resting on Dean's shoulder, this is for you.
More from me:
I love the roll of its sentences, the precision of its dialogue, the way it lingers and re-lingers on road markers, and--as you've mentioned yourself--slips across time and slips one moment next to another and somehow creates a new space in the rearrangement. I just want to breathe in the language of this, its images and places and also its Winchesters. Just gorgeous.
This is one of my favorite lines: In Illinois the week before Sam slept off a funk while Dean watched, him and news of the weird and him, breathing, quieter with Dean sitting on the bed, legs stretched out, one hand on the pillow near Sam’s ear.
Because I think what this fic does best, even as it skirts directness and revels in the esoteric, it's also so deeply grounded in every moment it touches, is still material even in flight. Which ties back quite well to the summary you've offered for it, and the crows with their crowns.