@Veronica Tower maybe flip your thinking, he liked having Rashta at his because of those things. Look at how he's treated her I don't mean the blatant favoritism the stuff around it. He didn't want her to become educated, till it suited him. Wanted her to remain ignorant of her real situation and what's going on around her, even if it makes her look a fool. He's told her he was to take her child from her, and give it to another woman. He set her up as an empress to fail. He saw Navier as below him power-wise, but he still saw her as a person. She's more than a match intellectually (she was raised for it), independent, and doesn't consider him to be superior, and it bothers him. Rashta and the other hand, a former slave, was completely dependent on him. Uneducated, childish, with no political know-how or powerbase, easy to fool and manipulate, easy to handle, servile, and used to have a master. In essence, controllable. She's not a person to him, she's a pet, that he can play with and then discard whenever he pleases.