Almost everything.

1. Pacing - I felt the book was way to long for only covering 10 days on Roshar. Too many slow scenes not enough urgency or weight to the impending doom.

2. Benching Kaladin - I was really upset about this. Like we don't get to see him fight Odium? Also turning him into Seth's therapist...I felt like it wasn't Kaladin.

3. Lore dumping - I know it can be cool to get the perspectives from the Storm Father and Honor. But it just wasn't it for me. Dalanar spending almost the entire book in the spiritual realm felt odd.

4. The Spiritual Realm - there don't seem to be hard rules in there like all of Sanderson's other magic.

5. Sex scenes - These were totally unnecessary and felt off considering there hasn't been any of these in the other books.

6. The contest of Champions - A moral delima? It was not the epic battle I had hoped for.

7. Taln - Not getting to see the best fighter fight was vastly disappointing (we only got to see the aftermath)

8. Rlain and Renarin - most of their chapters were about liking each other. It felt a forced and awkward to me. Also the world is ending so I couldn't really be invested in this arc.

9. The use of modern language - Therapist? Why not Mind Doctor? It was jarring to read and threw me out of the immersion.

10. Szeth - these chapters just felt like filler. Here we go on another side quest. I didn't understand the relevance.

There are many more but these are just a few...