More foreshadowing of the hanging man.
The minotaur doesn’t need to be big enough to shake buildings–just the ground when he’s near.
More longing between Dean and Castiel.
Maybe some stuff about the cult of the head to foreshadow what happens to Lorcan.
The walls of the labyrinth can only be seen when lightning flashes.
Instead of chapters, four sections, one for each grail quest.
Can’t decide if Castiel has the body we know or gets a knew one when he comes back.