@jak - I don't remember the exact points in the story but I don't think this is the first time something like this has happened. He also got the White Haired Lady killed (MC's master, don't remember her name). Also usually he acts and talks like a gentle person but as soon as something happens he is very quick to turn on the people he was showing affection to previously with no sympathy which makes it hard to sympathise with him. He is quick to judge, takes things at face value, loses temper easily, does not give benefit of the doubt, loses trust easily, is always being manipulated one way or other ( this last one has been my main takeaway of his character after reading the story upto this point). He is the Emperor so he should know people are going to try to manipulate him or sway his opinion but he does not maintain an objective point of view. Not saying all this is unrealistic, I know it was possible and maybe even common for Emperors to get people killed on their whims. Does not mean I like him or think he is a good ruler, he comes off as incompetent and fickle minded.
Well, this turned into a rant and a lot of hate for a side character. So i'm going to try to read this story again and see if it is justified as I've forgotten much of the finer details.
No wonder there are rebels, this emperor is trash and unfit to rule. He should have long since abdicated the throne to someone more fit cause he clearly never makes wise or calm decisions where it matters.