@Ruruskadoo unfortunately, in most of these scenarios, precisely
because he's a tyrannical prince not only does he have the power of life or death over her, but he could do a whole lot worse than simply have her killed given how corrupt this society appears to be (remember—the despicable act the Emperor got away with untouched—the same is likely true of the crown prince. Imagine what might happen to some lowly maid for attacking him for any reason. Chances are, besides si ply raping her on the spot, he could strangle her or worse, have her dragged off to be his sex slave and no one would refuse). It's all fucked, but logically consistent with the story. The author(s) and artist(s) are just underplaying the dark fantasy romance elements that are clearly present.
I don't think that she's a doormat. More, she's terrified of real dangers (plus, she is afraid of what he could do if she resists).