aigoo...I just spent some time writing a review, but then my laptop shutdown and I lost it T_T so I'll sum it up into a few words:

what I liked:
- production quality (the clothing, backgrounds, lighting etc. were nice compared to recent period idol dramas)
- JJS as the male lead. I've seen him in the King2Hearts and think his acting and portrayal of yi in was very believable
- park ye young as court lady dong. I've seen her in hometown cha cha cha and didn't know she was good at sageuks! she looks like a different person! In fact I think she should've been cast as the female lead instead!
- the veteran actors, who acted the court ministers. although the bad uncle guy looked like every other bad guy in these dramas, the older actor's acting was good and as expected
- the actor who played the grand prince (kid)
- I actually liked seeing that actor from crash landing on you in here as one of the shady ministers
(thinking....what else I liked lol)
- I liked when I realised it wasn't worth my time and dropped it...T_T

what I didn't like:
- so I may sound like a broken record, but shin sae kyung really wasn't the right choice for this drama. I don't think she's a good actress. As someone who's seen a few other historical dramas that are so much better, they should've picked someone who could've played the part better!
I've seen snip bits of her in rookie historian and I think she looks okay in idol drama but not in a more serious drama filled with more experienced actors! she looks so out of place! whether she's sad or happy it's unclear most of the time, because her acting is so stiff and she looks likes she's crying most of the time or about to cry. she also shakes her eyes around too much.
- the "romance" was so unconvincing! I felt bad for JJS who was really giving his best, but the female lead made the kissing scenes awkward and I didn't feel much chemistry between them..
- the pacing. tbh from episode 1 I was waiting the whole time for the male lead to find out about her identity! I didn't really care about the rest of the plot and when he finally finds out in episode 7 I think I was happy but then the drama just went down the drain.
- the female lead's character was really badly written
- the cross-dressing was nonsensical and made us and the other men look like idiots. also..she was initially dressing up as a "man" to save captives from Qing by earning money with playing Baduk/Go, but it never actively showed her freeing anyone and also does she have power to free anyone?
- the bad writing
- female lead's revenge plot was weak
- I liked that the music wasn't a bunch of kpop like in idol dramas, but I feel like they could've put more effort into the instrumental OST because that's sometimes what tends to carry these historical dramas

Overall this drama is pretty forgettable and such a waste of like 12hrs of my life!
After a while I wondered why I was even still watching it

also I just remembered something which makes the female even more stupid! why'd she want kim myung ha to help her when he was the one who wrote the false attestation?!

also I thought myung ha was better than the female lead because he could actually act lol, but overall this drama isn't the best. maybe it's better than others, but meh

but all that to say, would this drama have been better if SSK weren't the female lead? maybe, but I guess we'll never know...