For as much as people compare Empire of Storms with Tower of Dawn (because timeline fits) I actually think (with that aside) the book most heavily parallels Heir of Fire.
To the point I think it impacts Queen of Shadows so drastically & negatively for Chaol… because while Aelin had time in Wendlyn (not a vacation… it was its own hell) she was able to go through the motions: to be tired, to be hopeless, to be angry, to fight, to project & word vomit & hash it all out at its worst, to cry & break & grieve, to train & re-train, & learn, & think. So, she comes back into Queen of Shadows as someone else, because the broken girl (while still not fully healed… not sure if she ever would be) is now on the right track.
Meanwhile, Chaol isn’t there (yet). It’s part of why I think there is so much tension in Queen of Shadows (to the point of loathing & envy that leads to him acting like she was on “some soothing vacation” instead of acknowledging the hell she walked through & still carries heavily).
I’d even go so far as to say it makes Tower of Dawn more of a healing story (as it’s meant to be) & less of a “redemption arc” (because he’s not a villain that has fallen from grace… he’s just a man; a very young man, with a lot of trauma, who has made some very bad decisions that have detrimentally harmed people; including himself).
So, he does the same things that she did: he goes through motions, he gives up & he tries again, he learns & unlearned & reforms, he falls & he breaks & he re-breaks & re-opens, he rages, he grieves, he fears, he fights & hashes it out & projects it, he overcomes & grows; again & again & again… growth, that's the real story they both go on (especially in the latter).
Down to the final battles with quite literal “inner demons” & the Pandora’s box of secrets & traumas that they must open up & face (which they do).
And when they each leave their separate books, hand entwined with someone else; they’re someone else too. They enter a new life. Kingdom of Ash is no longer two ex-lovers, young, and bleeding, and ready for ruin. It’s two adults (perhaps too old for their still young age; weathered & scarred) but they are not actively bleeding from it (from them) they are on the same side, clearly, fighting for a better world; one they all make it to together.
