I have read that this is the sister piece for Princess Weiyoung, so I was a little unsure. Personally I liked this show better, inlace of silly "harem" backstabbing, this was a semi-intelligent political backstabbing drama, Every once in a while the show lost its intelligence.... example the assassin leader that raised them and only wanted revenge changed his mind in like 5 minutes which was a let down. Mainly though the show had intelligent people and stayed clear from the normal overly simplified bad people.

Here's what I liked....
the acting was great especially ML and FL. I have never seen the ML in another show and was very impressed with his acting and portrayal. The FL has always been just OK when I see her, not annoying but not one of my favorite actresses. Her acting in this show convinced me she is good and just needs better roles. All of the acting was great, the Royal Mother was the only one that was over the top with her acting and the second ML was clearly out of his league. Watching him vs the ML it was glaring how much of a gap there was. Hopefully he gets better over time. I liked the relationship between the ML and FL leads. While they were not overly romantic, it was mutual trust and caring for each other. I look at that as more realistic and lasting love vs the physical love. SPOILER ....I also really liked that the 2 brothers didn't turn on each other and remained close despite some instances where there seemed to be a distance,
I love the family relationships with the FL and her family - both her real family and her adopted assassin brothers
The story was solid, maybe a little too long, but it kept me interested. Again I was happy to see the FL being friends with the Princess (other wife) and good friends with her sister-in-law. Of course the adopted sister was bad, but that was the only harem type action besides the royal mother. With that said it was more interesting than a Princess Weiyoung where the ML was stupid 90% of the show, and everyone was a cardboard villain or harem girl. However, it wasn't the most complex plot either. Do not confuse this with The Rise of the Phoenixes.

Here's what I didn't like....
The last villain, I get why he did it but it was like all of a sudden here's the "real" mastermind out of no where, but we will still solve that in like 2 episodes. It took over 30 to remove the first bad guy and he was being used by he mastermind. Crazy how easy it was to catch him.
The production value was OK, clearly not a giant budget and shows should stop showing people riding horses in closeup... it looked so bad I laughed out loud.
Music was OK, I cannot say I remembered any songs or melodies. One background music sounded like music from another show so it was distracting.
The ending was not as bad as Princess Agents, but I have no idea what it meant. SPOILER.....Some people say she wasn't;t dead and the 3 year time jump was there little cottage where he was protecting her from emperor's edict. That doesn't;t make sense because the Prince was happy and had an imperial order, so there was no reason to hide her other than to prevent gossip? of course why the FL would drink poison and give up so easy is a mystery, unless she really didn't want to cause any additional issues for him (I mean the bleeding knees from kneeling, etc.) but if that is the case where was her body. My take is that she killed herself with the poison in the garden and on the swing. He basically is in denial and couldn't;t see her as dead (so no body on scree) and 3 years later he goes to the cottage and cooks all of the food poorly like she did and basically still acts like she is alive. Probably not worth watching the last episode since there is no closure (other than the new laws are god and helping people and the ML and second ML have really ugly looking mustaches!)

Overall... I have this as an 8/10. I may change it after a bit, I tend to make my reviews even lower the longer I think about a show.