As for the mirror case, I have my own theory which I have posted on the general forum but I can post it here as well.                                                                                                                        Well, mirrors mean they portend misfortunes, etc. And this mirror shows your fears, doubts, things you want, things you miss. Therefore, Jang Uk will ask for the opening of Jinyowon, a place where only members of Jin's family can safely enter and exit. Because, as Jin Cho Yeon will say, "You could be possessed by sorcery and be unable to return," Jinyowon collects items possessed by evil spirits. So three people will come into the room to find Mu Deok. And everyone will go through the mirror. And everything they see will be untrue. Go Won will see Mu Deok whom he desires and wants her to come to him. Seo Yul misses Naksu and Mu Deok reminds her. The last vision is not the vision of Jang Uk's but Naksu's. After meeting with the Crown Prince Naksu, knows that the duel will be fatal and that Jin Mu wants Jang Uk's dead, so she is afraid that she will have to betray him to save herself. Another vision also belongs to Naksu's, she fears that Seo Yul will eventually recognize her and will want to capture her. These are all just their delusions. Naksu will overcome them and lead them out of Jinyowon, because she is a member of the Jin family ;)

 Kim Hee Soo:
The look of shock from daddy Jang about the request was because he knows soul switching was illegal and he didn't think King would be using his body to impregnate his wife.

Well, I still wonder about this part. Jang Kang didn't object too strenuously when the King ordered him to switch souls so the King could father an heir. It was pretty much "I'm shocked and don't like it one bit, but I will obey your Majesty"

Then when Jing Kang woke up in the King's body and read the King's note that  said "I shall make Do-wha mine", he went ballistic "That cannot happen", "Jin Mu bring me the Soul Ejector",  "I  have blocked his gate of energy.  I forbid anyone from opening his gate of energy!'', "I'm leaving for 20+ years without telling anyone why" etc.

Would Jing Kang have done all that if the King had slept with a random concubine (if that were possible)? So there seems to be something more involved than the illegality of non-consensual artifical insemination by soul-switching.

No doubt the correct explanation is the obvious one:  Jing Kang didn't realize the King was going to sleep with his wife (probably he should have), became enraged when he found that out, needed the Soul Ejector to switch back their bodies after seven days, and did his best to protect Jang Uk from what would happen if it was discovered he was born under the King's star. 

But I do feel like we don't yet have the full story of the events around Jang Uk's conception.

Bu Yeon went missing over ten years ago, so she could have been a teenage girl, maybe she was about 15? So it was after the birth of Jang UK and the terrible event in Cheonbugwan. This could mean that Jang Uk was able to play with Bu Yeon as a child. Who does he see in the eyes of Mu Deok, Naksu or Bu Yeon, or maybe both? It gets even more confusing :)

 Izyda:

Bu Yeon went missing over ten years ago, so she could have been a teenage girl, maybe she was about 15? So it was after the birth of Jang UK and the terrible event in Cheonbugwan. This could mean that Jang Uk was able to play with Bu Yeon as a child. Who does he see in the eyes of Mu Deok, Naksu or Bu Yeon, or maybe both? It gets even more confusing :)

Your theory of the  mirror/scenes being delusion is a very good one. Lets wait and see.


Not only Uk but Dangu and Yul  coud have been playing with  Bu Yeon.  So definitely The Mudeok´s body is not Jin´s daughter or there are many people who would have recognised her.  Probably Bu Yeon´s  soul is inside that blind body/Mudeok. Why? We dont know at all. And now  there are two souls, Bu yeon and Naksu inside her body. Confusing as hell. I hope everything will be explained. 

 Cau:
 So definitely The Mudeok´s body is not Jin´s daughter or there are many people who would have recognised her.

But Heoyeom recognized her ears. We don't know how long she's been missing. Some people change a lot from infancy to adulthood. Also, looks like Choyeon doesn't remember her sister, so either the age gap between the two is big or they were both really young.

 jxxwxxstan:

But Heoyeom recognized her ears. We don't know how long she's been missing. Some people change a lot from infancy to adulthood. Also, looks like Choyeon doesn't remember her sister, so either the age gap between the two is big or they were both really young.

Oh i forgot about this! You´re right, he recognized Mudeok´s ears. This is a good hint. 

In the last episode Jin´s Mom and Jin Cho Yeom talked about a decade and her room is there waiting for her return.   

This story about mudeok´s body and both souls are very confusing indeed.  we need more hints! haha

 Izyda:
Bu Yeon went missing over ten years ago, so she could have been a teenage girl, maybe she was about 15? So it was after the birth of Jang UK and the terrible event in Cheonbugwan. This could mean that Jang Uk was able to play with Bu Yeon as a child. Who does he see in the eyes of Mu Deok, Naksu or Bu Yeon, or maybe both? It gets even more confusing :)

I think Jang Uk, Yul and Gang-Gu are all about the same age; Yul might be a bit older.  Cho-yeon is several years younger.  I think Bu-yeon is close in age to Jang Uk (who is 20 years old), so she disappeared when she was 10-11 I would guess.  

Ok.

So i review some scenes to pay attention to the swords the characters uses after i saw a comment  (@chrish ) about the "golden power" from Jang Uk netflix photos.

About the Swords:

In the main poster Jang Uk is carrying Naksu´s sword. Both Jang Uk and Mudeok are using new clothes i believe is probably after they gain their powers. 

Naksu´s sword :  Half black, half white with golden details. 

Jang Kang´s  sword (father): a long entirely black with many golden details. 

Crown Prince´s sword: a long entirely white with many golden details. 

Jin Cho Yeom´s sword : a long red one 

Seo Yul´s sword : a long dark blue

Park Dan Gu:  He used a sword in the fight at  first episode but i cant exactly see the color but its dark. Could be black.  Could be dark green since its his color.  He uses a green bow. 

Park Jin´s sword (uncle):  A black one

SO i believe this details are connected especially being in the main poster.  Naksu´s sword is a mix of black and white. Could it be a hint of Uk´s paternity  - that is a mixed of Royal blood and Jang family blood?  Uk´s outfit is also black and white.  i think is too much symbolim to be just casual. 

And Why Uk´s is using Naksu´s sword? He could uses his father or a new one made for him. 


( i have prints of the swords but i couldnt post photos here...)

 Kathryn_51:

I think Jang Uk, Yul and Gang-Gu are all about the same age; Yul might be a bit older.  Cho-yeon is several years younger.  I think Bu-yeon is close in age to Jang Uk (who is 20 years old), so she disappeared when she was 10-11 I would guess.  

I think that Four Season squad is in the same age, i.e. they are 20 years old, or the difference between them is small. Bu Yeon was the oldest of them and is probably Naksu's age - about 25? Jang Uk was born 20 years ago. The events of Cheonbugwan took place 20 years ago too. Naksu could have been around 5 years old then, or maybe even more?

So, Jin clan's missing elder daughter - Naksu or Mu-Deok?

Evidence for Naksu:
- she was addressed as lady when she was a child, meaning she's was of noble birth;
- there was a massacre and she is presumed missing or dead, just like the case with missing Jin clan's daughter;
- Jin clan is matriarchal, so her father's position wasn't that of a leader - he was a constellations recorder;
- all this talk of birds and eggs in a high nest in need of sheltering - Jin clan's matriarch seems to be very fond of birds, she has lots of them in cages, and she contemplates them longingly. Maybe Naksu used this metaphor to talk about her childhood;
- she was a powerful mage;
- Naksu is not her real name, but a nickname.

Evidence for Mu-Deok:
- her weak body somehow still able to keep Naksu alive and not become petrified, even though she lacks energy - was she a mage?;
- something strange about her soul, it wasn't ejected from her body - again, was she a mage?;
- she can sense Jin clan's artifacts for what they are even when they're hidden in a box. This surprised Naksu, however if she's the daughter she may have been too young to know about this ability, or it may not be Jin clan's ability but the body's she inhabits;
- judging by the preview she can open (unless she was lured into it) Jin clan's artifact vault, even though only clan members can do it. However, again, if the daughter is Naksu the vault may be reacting to her soul, not the body.

So far I think there is more evidence for Naksu, however the last two points for Mu-Deok are pretty strong, but only if it's not Naksu's abilities. Could there have been two girls missing from about the same time? I kinda doubt it.

 Aramintai:
So, Jin clan's missing elder daughter - Naksu or Mu-Deok?

I want to avoid a MDL war over this, but the evidence that "Mu-deok" is really Jin Bu-yeol is overwhelming and I believe the writers and production team began hinting at it before the show began. Some of the following was posted early on but it got buried in the China/Korea plagiarism battles and the "ratings" battles.  More clues followed but here goes:

●  Clue No. 1 [Credit goes to commenter “Sominah J“ for being the first to notice this]:  In addition to the Four Season photos/short video clips, there is one of Mu-Deok.  MD’s background is cherry blossoms – just like Jin Cho-yeon. (This was before the show began)

● Clue No. 2: Official web sites [tVN and Han Cinema] described the eldest Jin daughter as “missing” or “lost”.  (This was before the show began)

● Clue No. 3: According to Joo Wol, Mu-deok “speaks eloquently” and reportedly “sings well”, hinting at noble family upbringing [Ep. 1]

● Clue No. 4:  Heo Jeom recognized Mu-Deok’s ear [Ep. 3] - a physical  piece of evidence

● Clue No. 5 (confirming Clue No. 2): Eldest Jin daughter is “dead” (Ep. 3), “lost” (Ep. 4) and/or “missing” (Ep. 5). Unclear if different words were intentional or a matter of different Netflix translators.

● Clue No. 6:  Eldest Jin daughters has only been gone for over a decade. [Naksu was apparently taken 20+ years ago since Jang Kang was there at the time and all of the other mages appear as they did in other scenes from 20 years ago]

● Nail-in-the coffin Clue No. 7:  Only a member of the Jin family can open the door to the Jinyowon vault. 

Mu-deok is Jin Bu-yeol and I have no idea where she's been for over 10 years but I'm convinced she wasn't training at Danhyanggok.

 Kathryn_51:
In addition to the Four Season photos/short video clips, there is one of Mu-Deok.  MD’s background is cherry blossoms – just like Jin Cho-yeon. (This was before the show began)

https://www.youtube.com/watch?v=3hD40853rD8
In this video, if you fast-forwarded to the scene where they filmed Mu Doek holding the sword (that was Naksu's sword too) under the tree that indicates she's also Spring, which further concretes the theory. She changed her clothes and hairstyle too. Maybe sth was revealed? She got her position as the Eldest daughter of the Jin Family back? But that styling is still too simple to be that of a noble lady. She then stands on that bridge with Jang Uk.

 Kathryn_51:
I have no idea where she's been for over 10 years

In ep 1 they said after she lost both of her parents (I think they died), she got taken in and raised by an old woman. Also, we don't know who was that old lady at the beginning who got herself killed with her son sucking out the energy from her soul yet too.

About the video, in the photoshoot, Jang Uk hides her right eye, does that mean he wanted to hide the truth from her? but her left eye is uncovered though, so he might just conceal some truths, but not all of them. Then that shot when she held a sword at him. Hmm.. hairstyle and clothes changed, but her clothes aren't completed. So she got her power back, and she can unsheath her sword again, but had some argument with Jang Uk?

About the poster too, why is Naksu's sword in Jang Uk's hands instead of Naksu / Mu Doek?

 Fujihara Tomomi:
About the video, in the photoshoot, Jang Uk hides her right eye, does that mean he wanted to hide the truth from her? but her left eye is uncovered though, so he might just conceal some truths, but not all of them. Then that shot when she held a sword at him. Hmm.. hairstyle and clothes changed, but her clothes aren't completed. So she got her power back, and she can unsheath her sword again, but had some argument with Jang Uk?

About the poster too, why is Naksu's sword in Jang Uk's hands instead of Naksu / Mu Doek?

I don't try to interpret the posters very much except to notice that when her hair is long with front pieces tied back or braided, she looks exactly the way she appeared when Jang Uk first saw her (Ep. 1- she was beautiful but he only saw her eyes) and in the two posters/early promotional videos.  It is similar to Cho-yeon's hair style and I have taken it be the hair style of a young noblewoman.  It's the only time she has appeared that way in the show.  There's a reason they show her with Naksu's white sword and there's a reason that sword is now sitting in the Royal Palace, but I have no idea what may be.  

 Kathryn_51:
there's a reason that sword is now sitting in the Royal Palace, but I have no idea what may be.  

I wondered why she gave her sword to the Crown Prince too. If she wants to get her power back, shouldn't she keep her sword by her side? Or she thinks it's not the right timing?