Reili
On the top of my head, I remember that we need to go back to Nyx World where Iriel was sealed to save the sisters as promised. There's also Aekari who wanted to come apologize to Shiro and beg pity for his daugther since we stole Lyssandra. Also we need to save Lyrica parents and take revenge on the... Watcher?
Yeah, sounds like you're discovering/rediscovering the reason I write far more in notes than in chapters - for every 1000 words I've put into the actual chapters, I've probably written 15000 to 25000 words in notes. 15 to 25 times as much, yes, but I expect that's going to go down as I actually get further into the story (a lot of the notes I've got are for books 3 through 7, but I haven't gotten halfway through book 2 yet). It's still likely to be at least a 2:1 ratio though, as I have a lot of notes explaining the specific mechanics of something that I have no intention of going that far in detail about - but I want to make sure I have a solid foundation to keep logical consistency. Nobody's gonna know the exact details of what happens to a soul after it dies, but since the MC is going to pay that region a visit while alive, I figured I'd make sure I have a solid idea of what goes on there even behind the scenes, so I can mention parts of it as lore ("Such an evil man, he'll surely be toiling in the Karmic Mines for hundreds of years when he dies" kinds of things) well in advance without making anything harder on myself later on. Another reason notes are so important for me is that I do tend to take long breaks from writing for health reasons... and fairly frequently at that.