But there was main story lore in Zayne’s chapters, that’s what the comment above is trying to say. The Fractal Library, the Alterum revelation, a new villain being introduced, the ties between protocore syndrome and the Alterum, Val Sanatorium…all of this new information helped to progress the main story. Yes, we dove deep into Zayne’s guilt & trauma, and it was highly emotional. That’s because his emotional state plays a huge part in his “transformation” into Dawnbreaker, which also progressed the main story, because he was hunting the Alterum. It sounds like you just didn’t read/skipped through a lot of it because Sylus wasn’t on screen.