I think i'ts tuly not about him learning more about her. He's been with her the whole time, he knows her plenty. He just denies her, his pride is hurt by her excellence.
I feel like since being an emperor was natural for him since he was a child, he feels the need to fulfil some kind of power fantasy and he's upset he can't use her for that, so he naturally turns to poor Rashta who serves his purpose well.
Meanwhile he turns on Navier and twists his image of her to paint her as a cold, cruel woman to relieve his guilt for betraying her, who's been on his side their whole life, by placing the blame on her.