Aramintai:

It looked like the souls of the dead can inhabit living bodies in all the scenes. Not ressurection of dead bodies and souls inside them.

Ahh I see. So it's not possible to bring him back. *sigh of relief*

 Fujihara Tomomi:

Ahh I see. So it's not possible to bring him back. *sigh of relief*

i think your question is a good one, since Jin Mu took his petrified body inside Cheonbugwan  and we dont see they throwing it at the Lake nor  mention.

Buuut i dont think they can bring him back to life. 

 Kathryn_51:

My notes say that the Soul Ejector "powder" allows the following:

(1) one could bring the dead back to life by summoning back their souls

(2) one could shift souls from one body to another

(3) one could even expel the souls of the living and steal their energy.

I need to go Edit the "science of Soul Shifting" Discussion Topic.  

Number 1 is the most frightening.  Gil-ju thought that the Ice Stone could keep his body from petrifying (or, bring him back to life by summoning back his soul???)  But may not be possible with a petrified body.  

I need to edit the "Science of Soul-Shifting" Discussion Topic. 

You know what's interesting about this? Is the fact that soul shifting is Ice Stone's magic. And I'm certain there is a reason they've showed it change its properties: from ice-> to fire-> to stone-> to water-> to ice again. It's like the philosopher's stone in Western alchemy - a mythical object that can change lead to gold. And in Asian culture elements, transformation of elements and reincarnation beliefs go deep as well. I can't quite grasp what's the idea here, but perhaps soul shifters turning to stone is just the next phase in a cycle of transformation of matter. Perhaps petrified bodies can turn back to life if Ice Stone power is applied. It's already revealed it can stop the petrifying process, so maybe it can reverse it as well. Or maybe it's just bollocks.

 scenesonabridge:

Quick thought here.. what if Jin mom didn't recognized Mudeok (JBY) because she knew her daughter is blind? Which was also why she didn't pay attention to the fact that birds behaved erratically just before meeting Mudeok or Choyeon mentioning that she can access Jinyowon on her own. Also to tie in that Heoyeom has seen the ear before... so he has treated her before for some reason and could be brought there by her parents.

Or she disappeared 10 years ago when she was a kid and she simply didn't recognize her as an adult. Also, those noble snobs don't pay much attention to servants.

Someone said on twt that part 2 could be about their previous reincarnations. I think this is really possible. 

 Aramintai:

I can't quite grasp what's the idea here, but perhaps soul shifters turning to stone is just the next phase in a cycle of transformation of matter. Perhaps petrified bodies can turn back to life if Ice Stone power is applied. It's already revealed it can stop the petrifying process, so maybe it can reverse it as well. Or maybe it's just bollocks.

Well observed! I was thinking why do they dump soul shifters' petrified bodies in that Daehosmth river? Maybe their bodies turn into magical water again. 

 Isabella Snow:

 Master Lee is very old. He's a student of the founder or Songrim. He is very powerful and knowledgeable. And he could open the Jinyonwon, so he is more likely a Jin.

He didn't open the Jinyowon's vault, he summoned the Gwigu from outside.  He's not  Jin, he's a Lee.

 Isabella Snow:

She looks like what Mudeok looks like now. This girl is probably a Jin clan ancestor.

Ep. 8 confirmed that she was the Jinyowon clan's leader.

 jxxwxxstan:

Well observed! I was thinking why do they dump soul shifters' petrified bodies in that Daehosmth river? Maybe their bodies turn into magical water again. 

That magical water theory might just work because we see how Naksu can find the strength or magic to unsheath her weapon only when she is in that lake. So yes there is definitely some magical or healing properties in there.

Could this be the lake that is a result of the rain that was summoned by the priestess? Perhaps.