Hmm, I understand to an extent that "that world" people kill people for looking at them wrong and no1 will even bat an eye. However, you have someone that LITERALLY massacres your citizens and you're lenient on your punishment because your wife asked you??? For real?
Edit: Yes, I know the author made it that way for the sake of the plot.. It's just completely random how like a day(or few days) later after the emperors decision, he's literally not under house arrest anymore.