So, the Emporer is meant to the be main character's motivations. The reader is not meant to be invested in his well-being because of his character, he doesn't have one. We are invested in whether or not the main character can get him back because we see the main character is getting progressively more and more invested in getting him back, which may start getting in the way of her escape plan and get her caught. It is an incredible feat that is built up throughout the novella as difficult, and we see that she was able to complete it through quite a bit of grinding (Gets college flashbacks). So, the lack of personal investment in the Emporer isn't really a flaw when it isn't even something that is intended.
As for the main character, you do not give any good points on why you're not invested in the main character except that you 'knew' she would not die. While I admit that it was highly unlikely she would die in the book, that is not a very good point considering you can say that for many characters, not to say knowing a character will not die can't break an investment, but you need a little bit more than that, for an example of what I mean, having an immortal character in a very action-filled book, you're not going to be invested in the character's action scenes because you know he will survive them all, something else besides his life needs to be put at stake to get our investment. That doesn't really work here, though, as her life is very much in peril and she almost does die several times, only surviving through careful planning, and her relationship with Gaotona was very well done, if small.
So you saying you're not very invested in the character is not informative or helpful and can be easily countered by me saying, 'I was invested in her'. You cannot really counter that, like how I cannot counter your lack of investment, but that doesn't really help anyone. Yes, you're not invested, but why, and again, the argument, I knew she would live, isn't very good. We often know that certain protagonists will live, part of the investment is HOW they manage to live. Like, you realize that if you read a book and know exactly every character that lives, I can still re-read it and be invested in those characters and their journey, right? You're argument is basically saying you can never re-read something and be invested because you know what will happen.
And, I know this is meant to be a 'chill and short review' and that this is a small book, but you can talk a little bit more, mate. It's not like you're editing this. You just need to set up the camera, record, and then post, and I don't believe you're reading of a script either (Which isn't necessarily bad, but that also means that these should be easier to make than a scripted video.) You're skipping over a lot, and you can try and elaborate just a tad, talking for two or three more minutes is not that hard. Like, you did a series on Elantris, it can't be that hard to add a few minutes to an Emporer's Soul review when you're skipping a lot and barely saying anything. Put in a bit more effort, you clearly can.
@Honorless This video does not do a good job of explaining any shortcomings, so don't know how this is refreshing.