I harp on atmosphere a lot in my reviews (speaking generally, not specifically of your work), and right away, this chapter shows off why it's so powerful. This seems to fit rather well with the talk of hyperphantasia, as well. Before we ever see Annora, we experience what she's experiencing: cold, clammy tunnels, darkness interspersed with bio luminescent glow, echoes, staleness. We get a sense of sight, sound, feel, even smell and taste. All in a paragraph, a measured introduction that sets the tone.
Then when we do see Annora, her physical countenance emphasizes the effect her surroundings have had on her, even before the bleak reality of her mental state gradually reveals itself throughout the chapter. On the whole, the writing feels quiet but powerful, and it's easy to capture Annora's desperation and resignation at war with one another. From a meta level, I love seeing the rambling about the Vis, things that I know are nonsensical according to the religious teachings that are in place, but which seem potentially obvious from a reader's perspective. A barrier formed from preconceptions that have taken powerful root.
The portrayal of El and Keydis here is haunting because they're so completely out of character there's never a moment when you doubt they're a figment of her imagination, and yet the fact that they're able to provide some comfort, even if only for sounding off ideas to herself, kind of makes me miss the days when we were writing together regularly. For that matter, I miss when I was able to write regularly at all.
This chapter opens up with darkness, cold and stale air, hope lost after literal years of being trapped in a prison with no escape. So the contrast at the end of the chapter, where she begins to feel sympathy for the deities and begins to draw out heat and light from her sword, rekindling her hopes with a promise to return, feels all the more powerful. Looking forward to seeing the rest of her journey, to see how she fans this spark into a flame, and to seeing what changes have been wrought in Annora when all is said and done.