So Ep 8 confirmed the theory that the physical/human form Mu Deok houses 2 souls:
      a. Ice Stone in blind Mu Deok  
      b. Naksu in physical Mu Deok

How is this confirmed? Well, human form Naksu is not aware that Jang Uk did not switch souls. She wasn't aware blind Mu Deok was in that realm to save Jang Uk.

This confirms the theory too that the Jin Won storehouse was opened because she was Ice Stone and not the eldest Jin. As Ice Stone, she can command things.

At this juncture, being a Jin is irrelevant (coz Jang Uk won the match and is back at Songrim to be an official mage plus he has confirmed twice he is not getting married to younger Jin so why would he stay there when there is no relation to any Jin even if it is by invitation), I said at this juncture because we are not even halfway through the series (we have 12 more eps to go) and as Mu Deok advised Jang Uk, going to Songrim is the best way to go for now so there may be a need to go there or Cheongbogwan or even the Palace in the future but we shall see.

We don't know what's to happen except that we do know that more important people know/suspect where Naksu and Ice Stone (IS) are:

1. Master Lee - he saw the protective shield she had over Uk even when she was unconscious. On this note, was that the IS that was guarding coz Mu Deok/Naksu can't remember anything from that episode


2.  Park Jin (Uncle Park, Leader of Songrim) - he suspects the IS is out there and thinks (at this juncture) is the one that's causing the chaos, I believe he suspects it's in Mu Deok because he noticed how Jang Uk was able to master different levels of sorcery very fast after knowing Mu Deok. Although after the Gil Jo incident, he is suspecting Mu Deok to be housing Naksu too


3. Seo Yul - we know he knows because of the bird whistle and the imagery from the longing mirror

For now, we don't know if the Queen and Jin Mu know but we know they want Jang Uk because of his skills.

Speaking of the Queen, who is the Chois? How were they ousted from the mage society? Why is her revenge so deep that she wants to ruin the people at Songrim so badly?

On a lighter note, we may be looking at another love triangle coming up for Uk and Mu Deok, that of the visiting Lady Heo who he rescues from Gil Jo. Interestingly, she was not seen at the match alongside her grandfather (I am suspecting Heo Yeom as her grandfather). Why is she visiting btw?

 jxxwxxstan:

Well, she definitely still has part of the ice stone inside her. That's what's keeping her from running wild with Naksu's soul. I believe that's also how she could save Uk and break free from the mirror. 

I don't know how, but it seems to me that she's getting stronger with Naksu. 

She definitely does lol haha, even what Master Lee said seems to suggest so. A weak body with a strong soul.

I saw a theory somewhere that Mu Deok is absorbing Naksu's soul. Well.... if you look closely at her eyes, the light in her eyes isn't equally lightened. The left side is even brighter than the right eye, now why I'm sweating lol

 ennekube:
The question is how she knew to do it and if she’d done it before.

I place my bet on Jin Mu. His subordinates seemed to know how it works. It would be strange for a skilled one like Naksu not to know about it. 

 ennekube:
Just not sure how. 

We're stuck with it too lol hahaha

 Kim Hee Soo:
Interestingly, she was not seen at the match alongside her grandfather (I am suspecting Heo Yeom as her grandfather)

He is her grandfather, yes. You can read the characters' descriptions here: 

https://mydramalist.com/discussions/can-this-person-be-translated/73883-aos-character-descriptions-and-relationships-venue-descriptions-spoilers

 Fujihara Tomomi:

She definitely does lol haha, even what Master Lee said seems to suggest so. A weak body with a strong soul.

I saw a theory somewhere that Mu Deok is absorbing Naksu's soul. Well.... if you look closely at her eyes, the light in her eyes isn't equally lightened. The left side is even brighter than the right eye, now why I'm sweating lol

I place my bet on Jin Mu. His subordinates seemed to know how it works. It would be strange for a skilled one like Naksu not to know about it. 

We're stuck with it too lol hahaha

Well if Naksu was brought up by Jin Mu as Danjo and if his subordinates know it, why cant Naksu knows it? So yes Naksu knows how to shift and use her energy and agree IS is absorbing Naksu but not totally coz Naksu is still conscious of physical Mu Deok. That explains why she isn't aware of what IS is doing in the ream.

I found out about this in a BTS video, seems like Mu Deok is talking in a different accent? Idk anything about Korean, so lol. Ughh, does this accent come along with her as Naksu or Mu Deok? Mu Deok is from a village too.

 Kim Hee Soo:
not totally coz Naksu is still conscious of physical Mu Deok. That explains why she isn't aware of what IS is doing in the ream.

*sigh of relief* I hope I just overthink about it hahahha

Someone here mentioned that physical Mu Deok/Naksu's eyes are different i.e. the left is different from the right (was that your theory jxxwxxstan ?)

I actually didn't notice it and Jang Uk did say in the hut that her eyes have lost her blue mark, a nod to Mu Deok/IS consuming her soul slowly.

But what's interesting about the eyes is that it reminded me of another of the Hong Sisters' works, A Korean Odyssey. Remember how the eye was used to guide Oh Gong to find Sun Mi in the afterworld coz she died to save the world?

The scene where Jang Uk and Mu Deok were overlooking the Lake that is the grave of the soul shifter seems to be a foretelling of such an ending. After all, this is the Hong Sisters who are very notorious for not giving us happy endings plus its TvN producing, and we know how TvN is one who rarely gives us a happy ending and is really happy to kill characters we love.

So I am bracing for the death of Seo Yul and maybe Lady Heo while saving them. These two know their love is unrequited and knows both their love interests' secrets.

Considering Mu Deok is not actually human, to begin with,  if we are going by the theory that she is a human form of IS, she eventually needs to be destroyed to save the world either that or, she eventually gets consumed as a soul shifter and needs to be buried at the lake. Jang Uk being the person he is, obstinate, loyal and unrelenting, will follow her into the lake and use whatever strength he has (be it his King Star and/or Jang's gift - considering at this point Jang Kang would have come into the picture already) to get Mu Deok back. But we know Mu Deok cannot come back as her actual body has decomposed (if she is a soul shifter) or there is no actual body (if she is IS). So Jang Uk rather die and live with her in the lake. After all, he doesnt fit in anywhere and cannot live without her.

My crazy theory hahaha. 

Naksu and Buyeon are both the reincarnation of the blind priestess. Her soul was split in half and came to the world again as Naksu and Buyeon. Naksu has the physical capabilities and Buyeon has the magical capabilities. This happened because they wanted to prevent her reincarnation to produce something as powerful as the ice stone again, since it‘d only bring chaos to the world.  I still believe that Mudeok is Buyeon who had suffered some accident which resulted to her loss of memory and powers. And the ice stone or part of it is still inside Buyeon. In Ep 8, we saw that Buyeon can prevent the soul shifting, but in Ep 1, why didn’t she prevent Naksu from soul shifting? Instead, she absorbed Naksu’s soul. That proves that the two girls’ soul are related. I believe she did that because she needed Naksu’s soul to manifest something from the ice stone or from her soul. 

Seo Gyeong was also supposed to be reincarnated as Uk and the dead king’s son for the same reason. The late king was supposed to be sleeping with another girl that night when he slept with Dohwa. That’s supposedly how the late king’s son would be conceived. But because he slept with Dohwa who was already pregnant with Uk, the destiny of the late king’s son was transferred to Uk. So the supposedly four different people became only two. 

The ice stone that‘s in possession  of the Queen is fake or at least a different relic with the same but weaker abilities. Since the real ice stone can prevent the soul shifters from running wild. But all soul shifters we’ve seen had ran wild except for Naksu. 

Maybe parts of the ice stone were both present the two girls’ bodies. Thus, Master Lee can’t be sure it’s sealed because two girls could possibly control it.  Jinmu might knew about it, that’s why he took Naksu, and he might’ve been looking for Buyeon, she might be running away from him the day she lost her memory.  But now that Jinmu thought that Naksu is dead, his only hope is Buyeon. That’s why, he approached Mother Jin. 

But why did Cho Chung soul shift? What’s his motive? Or is he force to?

Also all drama posters have only one eye of ML and FL, excluding the character posters. 

 Kim Hee Soo:
Considering Mu Deok is not actually human, to begin with,  if we are going by the theory that she is a human form of IS, she eventually needs to be destroyed to save the world either that or, she eventually gets consumed as a soul shifter and needs to be buried at the lake. Jang Uk being the person he is, obstinate, loyal and unrelenting, will follow her into the lake and use whatever strength he has (be it his King Star and/or Jang's gift - considering at this point Jang Kang would have come into the picture already) to get Mu Deok back. But we know Mu Deok cannot come back as her actual body has decomposed (if she is a soul shifter) or there is no actual body (if she is IS). So Jang Uk rather die and live with her in the lake. After all, he doesnt fit in anywhere and cannot live without her.

If that's the ending, I'm going to be so depressed for months!! Tissue company gonna love this drama.

 wanderee:
Naksu and Buyeon are both the reincarnation of the blind priestess. Her soul was split in half and came to the world again as Naksu and Buyeon. Naksu has the physical capabilities and Buyeon has the magical capabilities. This happened because they wanted to prevent her reincarnation to produce something as powerful as the ice stone again, since it‘d only bring chaos to the world.  I still believe that Mudeok is Buyeon who had suffered some accident which resulted to her loss of memory and powers. And the ice stone or part of it is still inside Buyeon. In Ep 8, we saw that Buyeon can prevent the soul shifting, but in Ep 1, why didn’t she prevent Naksu from soul shifting? Instead, she absorbed Naksu’s soul. That proves that the two girls’ soul are related. I believe she did that because she needed Naksu’s soul to manifest something from the ice stone or from her soul. 

Ohh cool..... now I understand why people say their souls are split into two. Ahhhh so much to unpack!!!

 wanderee:
Seo Gyeong was also supposed to be reincarnated as Uk and the dead king’s son for the same reason. The late king was supposed to be sleeping with another girl that night when he slept with Dohwa. That’s supposedly how the late king’s son would be conceived. But because he slept with Dohwa who was already pregnant with Uk, the destiny of the late king’s son was transferred to Uk. So the supposedly four different people became only two. 

Sorry but Dohwa was not pregnant at the time because she's been left alone for a good year coz hubs, Jang Kang, was busy playing soul-shifting magic with Jin Mu (refer to Park Jin's conversation with Maidservant Kim in ep 8). So it's only natural that Doh hwa was so happy to see Jang Kang back and made love with him (or so she thinks), imagine the longing!

And King definitely wants Do Hwa because she was the prettiest girl at the time but unfortunately had already been married, so he being Jang Kang , was killing 2 birds with one stone (ok make that 3 stones) at the time:
1. get to be with the prettiest girl
2. get to be Jang Kang, having the strongest body (mages has to be strong in order to have all those magic)
3. get to have a kid (his top most priority)

He cant be with another lady, as someone here pointed out, and go to his favorite concubine coz he still respects (or is that being smart about the soul switching with) Jang Kang. Coz if Jang Kang is found to be with his concubine, then he should be punished and that's not good with the 7-day agreement they had. 

Fujihara Tomomi I hope I am wrong but Hong Sisters and TvN are not a good combination if you want a happy ending and dont hope for a Season 2. Hong Sisters never does one!

 wanderee:
But why did Cho Chung soul shift? What’s his motive? Or is he force to?

Gil Jo said he was made use by Jin Mu. Check out what he said at the start of ep 8.

I just want to know who Choi or the Choi family that the Queen mentioned in the secret room with Jin Mu is. I am sure that is the family of the Queen. She is not a Seo. If she is a Seo, why is she so bent on revenge and wanting to rule over Daeho? Technically as Queen and as Seo (as some here believe), the eldest and most respected mage family, she already ruled both worlds of Daeho.

I believe Choi is one of several strong mage families 200 years ago and was "tricked", or so she thinks, by Seo Gwang to hand over their powers to the 4 mages now or that the Choi family was killed in the chaos that Seo Gwang created with the priestess.

Now is Seo Gwang part of Jang Uk? I would love to believe like everyone here but why is his magic not seen or recognised by Master Lee? I mean Heo Gyeom recognised his master as soon as Master Lee entered so Master Lee should have recognised or felt the soul (considering how hi-level his magic is)? Instead, he sensed Ice Stone or Naksu's when she protected Jang Uk at the hut.

 wanderee:
Also all drama posters have only one eye of ML and FL, excluding the character posters. 

ooh now that you mentioned it...I had to look at all the posters again..and of course the main one. The couple shots are always that of their side views so yes only one eye of each of them is shown to us.

We know that the eye is the window to our soul, to depict that only one eye is shown may be a nod that they are one and the same soul. I.e. Jang Uk and Mu Deok are soulmates. The interesting thing is the main poster shows Naksu's sword, not Jang Uk's. So I guess the key lies in the power of the sword and what it means for them as a couple or soulmates.

Could the sword be the binding link between their souls? Who forged that sword? It is now safely hidden at CP's so let's see how it will resurface and helps us unravel their soul story.

Real Mu deok wants to end this whole Alchemy of soul, so she is looking for someone capable of fighting against everyone. So when she saw Naksu trying to soul shift, she takes the opportunity and absorbs her soul. Naksu and Uk must have some special connection cause Uk recognized her as Naksu by immediately looking into her eyes. Naksu is a soul shifter and Uk is a mage, when they are together, they can fight against anyone. But I think you guys should prepare yourselves to see death of some of the characters especially Yul and Songrim, cause I have a feeling that they would protect Naksu and Uk.