Just read these two chapters, some really great material here. My hear breaks for Proyas, though it's good to be reminded he's a consummate fanatic at the same time.
I keep coming back to the bizarre passage with the head on the pole, curious stuff. Given that I'm reading TDTCB again at the moment, it immediately reminded me of the chapter where Inrau goes to the temple of Onkis, whose effigy is first described as being the head of a woman on a pole. This pole is ultimately revealed to be the likeness of a tree, but it's a striking image nonetheless.
Onkis is described as the singer in the dark, who "stood at the heart of all men, moving them to grasp far more than they could hold", which to me seems sort of like what Kellhus is doing with Proyas here, pushing him beyond his limits.