This was so good! The world building is very good, the tensions are very strong, and the resolutions aren't easy. If there are two things I wish were different, they are:

1) Touraine's past could have been a little more fleshed out. That she's a lieutenant is really important to her both personally and in the narrative, but there's very little that shows why she's a lieutenant. She makes some incredibly bad judgment calls (which, fair, tbh. The story is very clear it's b/c of her own internal struggles), but a few examples of what she'd been like as a soldier that got her promoted would have helped.

2) Luca seems a little too willing to accept people from a culture she's been taught is uncivilized. In some ways, that's good - there's some good growth around her taking responsibility for her/her empire's actions, but it seems unlikely that she wouldn't have harbored any of her own prejudices to have to push back against.