@scenesonabridge 

“I would have thought that the path of least resistance is to curry favor with the ascending King rather than to complicate the situation by transferring a dying King's soul into another body”


By “ascending king”, Do you mean the crown prince? If so, I also think to curry favor with him is truly their initial plan. While the switching of bodies may just be their Plan B if things go south for them(for example, the crown prince being defeated by Jang Uk during the duel).
If the Soul-Shifter king think that the Crown Prince’s father poisoned him(if it was not just a chronic illness) to the point his body was unlivable, surely there would be no interaction between them. So the Soul-Shifter King must have thought that his best choice to leech into was his egoistic niece, the crown prince instead of his greedy brother.

Indeed, a more powerful body may be able to resist another soul more but remember the statement in EP2 where the body needs to be closely similar to the Soul-Shifter‘s body for a more successful switch? This may mean that the Soul-Shifter King is really still testing whose body is more compatible for him just like you said! He looks like he’ll soon become an evil soul-shifter so maybe time is running out for him to choose , thus made him to allow a duel to happen too. Oh no…

Here’s another theory:

If Jin Mu ordered Naksu to massacre mages in the pretence of extracting revenge for Naksu’s father, I think the Soul-Shifter King and JinMu has a plan.

At worse, this plan is to eradicate all mages in the future. Maybe for them to be able to raise the royal family’s power and erase all traces/history of Alchemy in Daeho. A really evil plan.

 jxxwxxstan:

This is not much of a theory, it's some thoughts I just can't get it over my head. The eunuch that Jin Mu is protecting, must be someone important because Jin Mu has been feeding and keeping him close. He could be the king (Uk's half-father). If that's the case, what is his plan? Does Jin Mu know Uk is destined to be king? What are they trying to accomplish with an army of soul shifters??

If the eunuch is not the king, why is Jin Mu helping him? What are Jin Mu's plans? We know the guy is an illegitimate child so he couldn't be the Jin family's successor, which is probably the reason why he's so ambitious. Just how far does he want to go? 

So help me out guys haha

the eunuch theory seem possible. if jin mu learned the spell and helped the king to switch bodies before he passed away. but then why would jin mu not help king's so called son Jang Uk as well? does he don't know about him?

Speculative theory:  Jin Mu is Jang Kang.  Twenty years ago, when Jang Kang (presumably evil--he was dabbling in forbidden sorcery after all) was trapped in the dying body of the King and asked his (naive-seeming) disciple Jin Mu to bring him the Soul Ejector, he used that to transfer his soul to Jin Mu, but (for whatever reason) he was unable to return to his original body. The Jang Kang who left was still the King.

Less speculatively: Naksu's family was killed because they were believed to be the soul shifters who ran wild 20 years ago (which would explain the presence of all the mage families) . Possibly, they were set up by Jin Mu.

@confusedpenguin

They probably accused Naksu's father of treason, but why were the families' representatives there to witness the execution? Did Naksu's father resist being arrested? She was really young back then and couldn't understand what was happening, she had to believe Jin Mu's words. 

@SlimXtra

I like your theory about Mudeok's soul! Naksu's body was really weak when she performed the alchemy, maybe she died before the alchemy was complete and Mudeok's soul returned to her own body. She's probably dormant because Naksu's soul is too strong.
Also, Heoyeom mentioned that besides Jang Kang there was another person who mastered the alchemy of souls. Teacher Lee must be the guy.

 Conservative_Torch:

the eunuch theory seem possible. if jin mu learned the spell and helped the king to switch bodies before he passed away. but then why would jin mu not help king's so called son Jang Uk as well? does he don't know about him?

Exactly. If the eunuch is the king, then he kept the information about Uk to himself, otherwise, Jin Mu would have to help/protect Uk. Keeping Jin Mu in the dark is too risky. Maybe he's waiting until Uk reaches his full potential to attempt to switch bodies, but considering how powerful Uk will be... that won't be an easy task.

 Thecla:

Speculative theory:  Jin Mu is Jang Kang.  Twenty years ago, when Jang Kang (presumably evil--he was dabbling in forbidden sorcery after all) was trapped in the dying body of the King and asked his (naive-seeming) disciple Jin Mu to bring him the Soul Ejector, he used that to transfer his soul to Jin Mu, but (for whatever reason) he was unable to return to his original body. The Jang Kang who left was still the King.

Less speculatively: Naksu's family was killed because they were believed to be the soul shifters who ran wild 20 years ago (which would explain the presence of all the mage families) . Possibly, they were set up by Jin Mu.

1 - We have the scene of both the king and Jang Kang talking after they returned their bodies.

2- That's possible, but soul shifting is easy to detect because of the blue mark, they wouldn't just kill anyone under false allegations. 

 confusedpenguin:
This may mean that the Soul-Shifter King is really still testing whose body is more compatible for him just like you said! He looks like he’ll soon become an evil soul-shifter so maybe time is running out for him to choose , thus made him to allow a duel to happen too.

That's a no brainer, his son is the most compatible besides being the most powerful. Also, the eunuch has already run wild, that's why he has been feeding on human energy. 

 Slim Xtra:
I still kinda hope that this is the case as the soul switch mark in Mudeoks eyes is "special" and this could mean there is a special circummstance behind it. There is one mark in both eyes so in total it means there are 2 marks on Mudeoks body, wich could mean one soul transferred back into Mudeoks body...

After re-watching many times and taking notes, I am convinced that you are right - Naksu's soul is sharing Mu-deok's body w/Mu-deok's soul.  The blue mark on Naksu indicates that the soul LEFT the body.  If there had been a blue mark on Mu-deok's body, it would have meant that HER soul LEFT the body - not that Naksu entered it.  Mu-deok's soul never left her body.  Anyway, that's my theory and the rest of this post is pure theory.

This is why Mu-Deok is so  hungry - she is feeding two souls.  

Finally, w/in a soul shifter, there is a gap between the body and the soul; the evil energy seeps out from it and can be detected.  Naksu's "evil energy" is escaping.  It's one reason she is no longer talking about killing everyone.  

Thus, theoretically, Naksu's energy is seeping out.  The body is trying to support TWO souls and even when Naksu felt the surge of energy from the Lake, it almost killed her and didn't last.  Accessing Uk's energy is going to be risky and challenging.  

Right now, I could easily see a scenario where Naksu's soul is slowly disappearing - in a normal circumstance, Mu-deok would turn wild or turn to rock but since MU-DEOK's soul still exists w/in MU-DEOK's body, the body will be A-OK.  Yul will eventually figure out what's going on and he will urge Naksu to leave peacefully (rather than attempting to shift into another body since she doesn't have the energy to do it).  The bad guys are beginning to figure where Naksu's soul resides and just as Naksu disappears, they come after Mu-Deok - the innocent.

 Kathryn_51:
The bad guys are beginning to figure where Naksu's soul resides and just as Naksu disappears, they come after Mu-Deok - the innocent.

Mudeok realized that the bad guys catched up as well.  To many of Naksus old comrades realized her fighting and presence therefore the trip to train with JanUk. In the preview I saw how master Hemp (the guy in simple pale clothing) realizes there is a mighty soul residing in Mudeoks body and he tries to do something to Mudeok while she is asleep. I guess he is not attacking her but helping her to stabilize her soul. I cant wait for the next episode and to learn more about Mudeoks/ Naksus state.

 jxxwxxstan:

1 - We have the scene of both the king and Jang Kang talking after they returned their bodies.

2- That's possible, but soul shifting is easy to detect because of the blue mark, they wouldn't just kill anyone under false allegations. 

1-Yes, I hadn't seen the scene with the King and Jang Kang talking near the birth of Jang Uk. But I still find it strange that the King seemed so sick when they exchanged souls, then so much better later after they returned their bodies, and we haven't yet seen what happened in between.

2-Well, Naksu's family could've been accused of transfering other souls (to the Eunuch, say, who maybe went wild 20 years ago) when they wouldn't have blue marks themselves. (Plus we know that the blue marks aren't always so easy to detect...)

But comparing Naksu's (assumed) father with the astrologer who observed the King's Star, they do look pretty similar, so I guess that's a more plausible theory (though are the mages really so bad that they kill a family to keep a secret?)

https://imgur.com/a/wTu4X8S

Hi guys.

I just want to point out that our answer to Mudeoks/ Naksus state, is probably in the reason why naksu´s soul couldn´t  reach the first girl she picked. 

Naksu´s soul choosed Mudeok´s body despite her choice.  I didnt see anyone talking about it.

And its pretty  clear now that Mudeok is the lost daughter of Jin´s family.

 Thecla:
2-Well, Naksu's family could've been accused of transfering other souls (to the Eunuch, say, who maybe went wild 20 years ago) when they wouldn't have blue marks themselves. (Plus we know that the blue marks aren't always so easy to detect...)

Yes, but remember that not everyone can practice the alchemy of souls? Heoyeom said the person needs to master Hwansu (the power to convert water into fire and vice versa), which is not common. 

 Thecla:
But comparing Naksu's (assumed) father with the astrologer who observed the King's Star, they do look pretty similar, so I guess that's a more plausible theory (though are the mages really so bad that they kill a family to keep a secret?)

https://imgur.com/a/wTu4X8S

It's the same actor ?? 

 Thecla:
But I still find it strange that the King seemed so sick when they exchanged souls, then so much better later after they returned their bodies, and we haven't yet seen what happened in between.

If the subtitles weren't wrong, the king said "thanks to you, the past 7 days have been wonderful" so the conversation was held immediately after they switched back their souls.  

 Cau:
I just want to point out that our answer to Mudeoks/ Naksus state, is probably in the reason why naksu´s soul couldn´t  reach the first girl she picked. 

Naksu´s soul choosed Mudeok´s body despite her choice.  I didnt see anyone talking about it.

You're right! We forgot to discuss that here. I don't have any solid point to create a theory, I can only guess by now. 

  1. Maybe Mudeok and Naksu are related? Like cousins or something, or sharing the same type of blood, I don't know. 
  2. Maybe Mudeok has a great soul inside a fragile body? 
  3. Maybe Mudeok was a soul shifter that got trapped in a weak body? 

Let's discuss!


@jxxwxxstan
  If the subtitles weren't wrong, the king said "thanks to you, the past 7 days have been wonderful" so the conversation was held immediately after they switched back their souls. 

That quote appears to be what the King wrote on a message left to Jang Kang right after they returned to their bodies. Immediately after that, the conversation between the King and Jang Kang starts with the King saying  "Do-hwa will be giving birth to my son soon" so the conversation must've been much later, just before the King dies (?). We haven't seen much indication of what (if anything) really happened when they returned to their bodies.

Anyway, I agree that Jin Mu being Jang Kang doesn't seem to fit, but with soul-shifting being the central conceit it seems quite likely that not everyone is who they appear to be. 

Some ignorable nonsense: What still makes me suspicious is  that Jin Mu in his initial conversation with Jang-Kang's-Soul-in-King's-body (JKSKB) seems much different (humble and obedient) from the later Jin Mu (evil and calculating). When the later Jin Mu recalls the conversation (in Ep3) between JKSKB and earlier Jin Mu, he thinks

 "He could not retrieve his energy due to the weak body he was in, which is why I was given a chance. I was lucky."

We're supposed to believe that later Jin Mu means he got lucky  because JKSKB taught him the Alchemy of Souls. But it could also be consistent with  JKSKB switching souls with Jin Mu, and the later Jin Mu meaning that he got lucky because after JKSKB switched souls with Jin Mu, the King's body was too weak for Jin Mu to retrieve his energy and recover his own body. As to what would happen if Jang Kang (JK) switched souls with the King (K), then JKSKB switched souls with Jin Mu (JM) to give JMSKB and JKSJMB, and after that King's-Soul-in-Jang-Kang's-Body (KSJKB) tried to switch back to JMSKB, I have no idea. (I suppose it should be KSKB, JMSJKB, JKSJMB, but no one seems to be turning into stone.)