You are not wrong, and in the novel it showcase that he did have feelings for Navier, but now with the divorce it will be displayed in a twisted jealous rage.
(spoilers)
Like one scene Navier and Heinrey(sp?) do come back the the E. Empire for his wedding with Rashta....during a dancing event Rashta accused Navier of doing something to her so she can lose the baby(￣へ￣). When all Navier did was ask her for a dance and was giving Rashta advice on how to run the empire as the new empress...I mean she still cares for her birth home-_-. Rashta was freaking out about what Navier was trying to do, that she had stress pains in her belly, and the emperor didn’t believe.
So the next evening when he came to Navier, our home girl assumed he came to accuse her for what happen...which ironically caught him off guard, lol. Which led him to feel insulted and confessed that how would he believe that foolishness. Which led him to feel guilty because he remembered he had in the past and confess he wanted her to return and not be another man’s wife.
Our queen told him no and you have other scenes that shows his regrets and his psychopathic obsession of Navier, which makes us feel better that she is with Heinrey.(￣∇￣")
Besides that long post, this all could have been avoided if he sat down and asked to have a heart to heart chat with Navier, not the empress, but just plain sweet Navier. Idiot #－.－)
i get the impression that both navier & soveishuu (his ugly ass name, idek if i spelled that right) actually loved each other (well, navier kinda confirms her side on 64); however, i guess their situation never allowed them to truly embrace that? seeing as how their marriage was always doomed to be labelles as just a political marriage - nothing more, nothing less.
even still, and this isnt me just hating the emperor for navi's sake, but i feel like the emperor recognized his feelings first. i think navi would've struggled a lot more to recognize she had feelings considering how emotionally collected she has to keep herself as empress. and it makes me wanna be even angrier at the emperor, because if he did have even the slightest bit of feelings for her, i feel like he could and should have just said something??? idk maybe take inspo from all these other fantasy emperors and dukes and at least attempt to woo navier??? (what a whole different story that'd be lmao)
like - assuming their feelings went both ways, which i don't doubt they did/do - the lack of communication between the two, especially from the emperor's side, annoys tf out of me bc it makes me feel kinda sad for them as a couple
anyways, he's a shitlord and i'm still yearning for his eternal suffering.