Another good theory was mentioned how Mu-Deok opened the Jin vault not because she's Jin clan's eldest daughter, but because the Ice Stone, the one which not only is involved in creating soul ejectors, but also all the artifacts, is inside her body. Meaning she can be sort of like the master key to the vault.
The plot will probably go Jin clan's daughter way, because it's a k-drama and in k-dramas big coincidences happen all the time. But still, I find this theory compelling.

It's also possible that the Ice Stone was stored in the Jin vault at one point. Jin clan's mother was upset that some Songrim mage deceived her earlier and possibly stole or was trying to steal smth from there. Maybe it was the Ice Stone and maybe Jin clan's eldest daughter got involved in that accident. So Mu-Deok can still be both - the daughter and the vessel.

 jxxwxxstan:

Rain is an important element here. Water really. Because Daeho's water is magical. Someone who mastered Hwansu is making the soul ejectors.
We see the original ice stone (hail) transforming into fire and stone before changing to water again and releasing the powder. Only someone who masters Hwansu can produce the soul ejector.

It was hard for Jang Uk to master Tansu. The sword needed to pierce through a water drop. The rain might have been advantageous because there are many droplets not one, and one could easily hit those rain drops and Jang UK's arms power combined, it was enough to create the effect of Tansu.

Wow. A lot has been happening in the drama yesterday

  1.  Mu Deok definitely seems to be the eldest daughter of Jin family
  2. Naksu's father was indeed a wild soul shifter
  3. Jin Mu has known about the birth secret all this time.

But we still don't know

  1. What happened to My Deok's original soul. Is it inside Naksu? Or was it a part of the same soul as Naksu. 
  2. How did Mu Deok open the door to Jinyowon? Is it because she was the eldest daughter? Or was it because of Ice stone? (Suggested by a previous comment)
  3. Was does it mean by ice stone is inside Mu Deok?
  4. How the hell it ended up inside Naksu?
  5. How did eldest daughter of Jin went missing?
  6. How did Naksu's father's became a soul shifter?
  7. What does Jin Mu wants to do? Just keep his position without giving it to Jang Uk? Or be the future king's personal favourite and destroy Jang Uk.
  8. What is the queen's relationship with Jin Mu?
  9. Why does Jin Mu needs an eunuch? Contact the queen in the palace?
  10. Why does queen provide soul ejectors to Jin Mu?
  11. What exactly does a soul ejector do? Swap the souls between soul shifter and the victim ? Or remove the soul from the victim so that soul shifter can enter the victims body?
  12. Does master Lee knows anything about the ice stone?
 Conservative_Torch:
How did Mu Deok open the door to Jinyowon? Is it because she was the eldest daughter? Or was it because of Ice stone? (Suggested by a previous comment)

Or is she related in some way to the blind (?) mage who performed the rite to bring back water to the lake. And was that mage related to the Jin family?


 Conservative_Torch:
How did eldest daughter of Jin went missing?

Jin Mu

 Conservative_Torch:
How did Naksu's father's became a soul shifter?

Jin Mu

 Conservative_Torch:
What does Jin Mu wants to do?

He wants to take over the Kingdom, control the Jin and other families, and destroy any who oppose him.

 Conservative_Torch:
What is the queen's relationship with Jin Mu?

Co-conspirators

 Conservative_Torch:
Why does Jin Mu needs an eunuch? Contact the queen in the palace?

I'd say yes. The eunuch seems completely expendable.

 Conservative_Torch:
Why does queen provide soul ejectors to Jin Mu?

Co-conspirators


Just my uninformed guesses :)

In the MDL introduction paragraph it's given as

"The fate of these people become twisted due to "hwanhonsool" (the soul of the dead return to the living)."

Hinting the return of dead king? 

I don't know anymore. I'll take anything as a hint at this rate.

 Conservative_Torch:

In the MDL introduction paragraph it's given as

"The fate of these people become twisted due to "hwanhonsool" (the soul of the dead return to the living)."

Hinting the return of dead king? 

I don't know anymore. I'll take anything as a hint at this rate.

It may be a Korean term. And one of the properties of soul ejectors is that it can return a dead soul into the living body, or vise versa but sucking out the energy.

 Kim Hee Soo:

If you have watched ep 7 you know how dense he is especially in Jin's storeroom of dangerous relics. The 3 of them boys are such a hoot in there!

Yeah, he was proud and dense hahahah

 Aramintai:
-Naksu's father was indeed soul shifted and done dirty. Somebody used him to cover up ML's birth record. Expected. But who was the culprit?

Mu Deok asked someone in the preview: "Was the man who shifted my father's soul, Jin Mu of Cheonbugwan? 

 jxxwxxstan:
Remember that a supposedly blind sorceress? priestess? performed a ritual to make it rain again in Daeho and bring the ice stones with it?? What if Buyeon is the reincarnation of that woman? 

YES, when I saw her dancing, I screamed internally, "MU DEO-, I mean BU YEON!?!" haahahah, what if Mu Deok and Jang Uk are the reincarnations of the Founder of Songrim and that blind sorceress?

 mesmeriz:
Really curious why you ship Uk with Jin Buyeon when we don't know JBY's personality, and neither does Uk. They might had a story in the past but we are not sure  yet and don't know how was their dynamic.

Unless... you are assuming the current soul in the body of Mudeok is a mixture (?)  of Naksu and JBY...

Since some folks were upset with my desire to see UK w/JBY, I've done some thinking about it and I think it is this:

In Ep. 1 and 2, Naksu was a murdering, remorseless "soul" who tried to poison Jang Uk for her pure selfish reasons (He was equally selfish, but he would never have done what she did).  That same weekend, I was preparing the Character Descriptions (posted elsewhere in the Discussion Topics) and I noticed that the Eldest Jin daughter was "missing".  My immediate thought/prediction was that she was "Mu-deok" and furthermore, if Naksu had her way, Mu-deok would be dead, never to be seen again.  I was certain that Mu-deok was the eldest Jin daughter and hint after hint was thrown at us in that regard, including a comment by Joo Wol in episode 1.

This is a show about "destiny" and twisted fates.  I never thought Naksuu was destined for Jang Uk.  

From that point forward, I have also believed that Jang Uk and Eldest Jin daughter are destined for each other.    I was confidant that her soul still existed (dormant) in her body and in fact I think that she has been why Naksu's soul has survived.  She is helping Jang Uk reach his destiny.  After Ep. 7, I am even more confidant that it is JBY's soul that is the "great soul inside the small body."

I just re-watched the mirror dialogue with Jang Uk and "Mu-deok" - they ARE destined for each other.  At some point, someone will either clearly identify JBL's face or her dormant soul will emerge.  And I don't need to know JBY's personality to know that since Jung So Min will be portraying her, she will be the heroine.  She may continue to be called Mu-deok, but her birth name is Jin Bu-yeol.  

@Kathryn_51  

Yea, yea, everyone knows here you don't like Naksu character and want her gone. But you gotta stop obsessing over it, otherwise you'll be disappointed if the plot won't go that way. Just watch the show with open mind, anything can happen.

 jxxwxxstan:

Hear me out, you guys... this one is WILD. Uk and Buyeon are the reincarnation of Seo Gyeong and that priestess. Can we consider them both as creators of the alchemy of souls? Technically the woman made the hail (ice stone) and Seo Gyeong created the soul ejector from it. IT'S THEM AGAIN, THEY'RE BACK!!!!

YOOOOOOOOO, that's just- I'm speechless. I can't even think straight anymore

 Aramintai:

The fact that the villain is part of the Jin family is reason enough to suspect he had a hand in Bu-Yeon's disappearance. That guy's incorrigible.

I wouldn't be that surprised if he were the one who did it hahahah, but bruh to your own niece.... this guy is beyond saving

 mesmeriz:
nless... you are assuming the current soul in the body of Mudeok is a mixture (?)  of Naksu and JBY...

Well, JBY's soul is nowhere to be found rn, so the best bet is that she's still inside the body.

 Kim Hee Soo:
Interestingly, she never projected any persona to Jang Uk when we know he's been thinking about her the whole time.

Maybe because he wasn't near a mirror when he thought of her?

 Kathryn_51:
Park Jin believes the Ice Stone was sealed long ago and it has now been unsealed/stolen to create Soul Injector powder.  Without a doubt, the powder exists – whether old powder from storage or newly created from the Ice Stone.

Remember when he asked Master Lee, "Are you certain that the ice stone was indeed destroyed?" Maybe it was indeed unsealed, and Master Lee encountered it somewhere and didn't destroy it. (of course, it's in Mu Deok's body)

 wanderee:
. that had side effects like losing her strength and memory and being blind.  she had to live her life as mudeok from then.

In Ep 1, after falling into the water, Naksu (In Mu Deok's body) said this body is unbelievably unhealthy. Maybe the reason that body is beyond unhealthy is because of the ice stone's energy? It might absorb the host's energy?

 Vniverse:
The Jin relics saying "it's her the blind girl!"

The Jins eldest daughter, she might be blind?

I think she must have been indeed blind before. The reincarnation theory (born blind) or she accidentally touched the ice stone theory might be the case. It's strange how Jin's Family never even mentioned Bu Yeon was blind, to begin with.

 Conservative_Torch:
How did Naksu's father's became a soul shifter?

The preview seems to suggest that Jin Mu did it, even Naksu asked someone about it. 

One more question to be answered. Are mages immortal? or do they just have longevity? Master Lee lived 100+ years, maybe the founder and Blind sorceress are still alive? It was 200 years ago too that famine happened.

Btw how I wish Madam Jin saw Mu Deok with that blindfold on maybe she might trigger some memories of Bu Yeon. *sigh*

Credit: Found out about this from the Currently Watching: Alchemy of Souls article, and here's the folk tale: https://folkency.nfm.go.kr/en/topic/detail/5786

"This narrative comprises two separate plot lines, one about Bihyeongnag’s origins and the other about how his divine powers were displayed. The union between the spirit of a deceased king and a living mother implies the union between the underworld and the world of the living, and Bihyeong, born between them, is a border and the medium between the two worlds. The mission given Bihyeong in the world of the living is to keep ghosts under control, especially to supervise goblins to build bridges and fortress gates, displaying the functions of a building god."


In the original tale, Lady Do Hwa and the Bachelor Bihyeong, Bihyeong  (the inspiration for Jang Uk's character) is the union between the livings and the deaths, so Jang Uk can be a union between the Royal Family and Aristocrats/mages? Since there's even an unspoken rule to never let the two powers fight each other so as not to waste energy. Maybe there's even more reason behind the rule itself. If the commoners win, the imperial rule will lose its power. But if the commoners lose instead, the imperial rule will abuse its power?

 Fujihara Tomomi:
Btw how I wish Madam Jin saw Mu Deok with that blindfold on maybe she might trigger some memories of Bu Yeon. *sigh*

At some point Father Jin will appear and identify her.  I've always thought ep 9/10 (halfway through the series) would be a major privot point in the main romance as well as some of the other stories (although we got a major pivot on the Danju today).      Just as they are getting close - bam, they discover Mu-Deok's true identity.