I'm still new to Historical Cdrama but really liked this one. I really liked the main characters who are flawed. Both of them at times come across as Selfish and it's nice to see that instead of perfect characters. Their childhood and circumstances play a huge part in shaping their personalities.
And their relationship took it's time to develop even though the ML falls for the FL early on, there is the fact he doesn't really understand her and when she brings it up, I like the way how he takes some time and comes back to her and explains things. At the same time even she introspects and wants to give it a chance.

The Emperor was amazing and the 2 Empresses ( I am gonna consider both of them as Empresses only) are amazing and their relationship with the Emperor and each other is shown realistically but I wish this extended to other female characters.

Things I didn't like - The amount of screeching by women characters. Even the FL's mother who is supposed to be in the military and who I think can easily order (control) people with just a look at times screeches.
There are a lot of female characters who are just reduced to be evil and manipulative (in a comical or dumb way) and the whole women being women's worst enemy ( even though we had one amazing Empress relationship) was way OTT.
The amount of time they spent on this, they could've shown it on the actual villains of the story.