Why is the Heavenly Maiden allowed to act so haughty in front of the Empress?
Where did she get her attitude from? Wasn't she just a girl before being sacrificed?
I get that the Emperor probably keeps quiet because he elevated her to that status for political reasons (probably to keep good relations with Jin Kingdom), but he should prevent her from talking that way.
Overall, I hate it when adult characters can somehow act so openly childish and are not being punished somehow for it. You just can't act that way and expect to be taken seriously in most places.