PhantomzK

Yes, he knows. Theres a flashback scene to his childhood in one of the episodes that shows his mom getting punished and he is a witness to it. Presumably thats how he learns of it and also why he kills the empress off when he becomes emperor. The suspicions surrounding the empresses death is the catalyst that sets off the tension between MZ and MC which eventually culminates to MC being killed too.

Huh. I guess I missed the part where a consort was in the picture,

Thats not what that scene was suggesting. He's simply not the son of the empress. Thats normal in a royal family. He was the product of a one night stand between the emperor and the maid, his biological mother. However, he was raised by the empress as her own son. The maid (His biological mother) was the accompanying maid of the empress when she married the emperor, thus why the empress was very angry and spiteful towards her. To her it was an act of betrayal by one of her most trusted subordinates.

Theyre unlikely to reveal how she regressed back in time. But in my mind it can be 2 ways all of which would add a bit of a magical element to it.
1. A common trope. Her regrets and resentments sent her back in time somehow. Perhaps time is irrelevant in the plane where souls exist. Of course it could also just be a figment of her imagination concocted by her broken mind.
2. The bracelet that the 9th prince gifted her might have magical properties.

Both are just some ways I would *justify* her regression from tropes I have seen before. The first one seems to be common in a lot of chinese manhuas.

She can't avoid the 2nd prince. The fact is that she has already caught his attention. He not only finds her families business useful but her skills and knowledge as well. We already know from the original route that he will do anything and everything possible to get what he wants. That is why the FL is caught in a net the moment she met him in both timelines. The difference is that in the 2nd timeline she already knows 'some' of what will happen and she also understands him and what kind of person he is and thus she is actively trying to escape his net. The problem is that she is the fish caught in the net and he is the fisherman in the previous time as well as this 2nd one. Her attempts at escape are mostly going to be in vain. Thus her best bet is to play into his palms and work her way out by gaining his trust rather than avoiding him. An enemy in the light is easier to fight than one in the shadows. In her previous life, he was the master manipulator in the dark from even before their meeting but this time she can become the shadow. But to do that she needs to stay close to him because she is the underdog in this fight. He can control her from afar because he has the power to do so. She doesn't and is mostly alone in this fight. Thus to beat him, she will have to join him first. Basically keeping her enemy close. By staying close to him, she can more easily know what he is planning and come up with a counter. If she tries to run away from him, she risks everyone close to her by putting them at risk instead.

Actually thats a good idea. I have been suspecting that Seo Yul had somehow moved Naksu's body somehow and that it never actually got burned to ashes. He had been hinting in previous episodes of wanting to bring something back with him to Seo Fortress which I had been suspecting to be Mu Deok and Naksu's body. It wouldn't really have made sense to me to just bring Mu Deok when he knew that she and Jang Uk were in love and not tell anyone anything about it.

Ok so this could be the case if Seo Gyeong had sealed her soul in the ice stone. This then begs the question of why Buyeon as a child clearly did not have Seolran's memories.

Where would he have gotten Jin Seolran's soul then?

Actually, I think the reason why she was born still was because she was the reincarnation of Jin Seolran. Of course all of these are just my own thoughts and we will still need to watch the next 2 episodes to see for sure. A lot of my thoughts are also a culmination of a lot of similar plots from 'cultivation' novels that I have read before. However, as I mentioned in my theory above, there is likely such a thing as 'Heaven's will' since there are things like Destiny and Divine/Sky power. Buyeon was never meant to be born in a time where such immense power was needed. The heaven's usually act in a 'passive' nature which is why people can manipulate its powers. It is only in extreme times where it becomes more 'active'. This would be in the births of heroic figures needed in such extreme times aka the existence of Jin Seolran and the King's Star.
One thing we also do not know is how powerful Seo Gyeong was. After all it was he who basically saved the world by destroying and sealing almost all of the ice stones that the entire world were after. So far we all know Hwansu as the strongest level of power for magicians but what if he attained a higher level?
There are still several questions that his love letter/will brings up. We know that he left the remaining ice stone with the Jin family in order to save his lover aka Jin Seolran. But she ended up dying anyway. So this begs the question of what exactly he meant to succeed in doing with the ice stone by simply leaving it there?
Another question I have is this: Why did the Jin family matriarch (Forgot her name) need Jang Gang to help her use the ice stone to bring Buyeon back to life? Could it be that those with stronger powers can wield the ice stone better and thus being the most powerful magician available, she found Jang Gang to help her? If so, imagine what Seo Gyeong could have done with the ice stone in his possession at the time, yet he couldn't save Jin Seolran despite the ice stone supposedly being able to bring the dead back to life.

Why doesn't it have anything to do with reincarnation? Reincarnations are essentially a preservation and passing down of ones soul somewhere into the future. The only real difference is the passivity of it as compared to soul shifting.

I strongly believe that Buyeon is likely going to die. I made a theory in part 1 already in why I think so.

Its a story about 'soul's' with 'Divine power' in the background and 'Magic' in the forefront. Seo Gyeong's will was the most important clue in why I believe this to be so. When Magicians attain Hwansu they can completely shift their souls into another body without repercussion. Then let me ask you this. What is above Hwansu? If an object life the ice stone can also shift souls among many other things, then how powerful was the priestess who changed the entire landscape and brought about the ice stones by manipulating the heavens?

She is powerful because she is the reincarnation of Jin Seolran who I believe is also an extension of 'Heaven's will', thus why she can manipulate what they call Divine or Sky power so well.

Here is my theory of the overarching plot of this series.:
Jin Buyeon is the reincarnation of Jin Seolran but Jang Uk might not be the reincarnation of Seo Gyeong. Seo Gyeong's will simply mentioned wanting to save his lover but does not say anything about being together with her once again. He simply wanted to save her because she was probably ill and weakly. Thus he left one ice stone in existence and left it with the Jin's hoping that, that could save Jin Seolran somehow. I don't think Seo Gyeong or Jin Seolran were ever meant to be together. Seo Gyeong existed to counterbalance the chaos created by the ice stones conception, but that was due to the actions of Jin Seolran. Thus, Seo Gyeong was the one who destroyed and sealed the ice stones. He never completely fulfilled his duties in entirety though because he fell in love with Jin Seolran.
Ever wonder why Jin Seolran and Buyeon are so much more powerful than anyone else even when compared to the rest of the Jin family? I think that both are essentially extensions of 'Heaven's will'. Jin Seolran was conceived during a time when divine intervention was needed for the land and thus why she had such immense divine powers (aka Sky power). But once she completed her duties, she was never meant to live a complete life, which is why she probably lived a sickly life and why Seo Gyeong wanted to save her with the remaining ice stone. At the same time, Seo Gyeong was conceived to counteract the aftereffects of the 'divine intervention' which was Jin Seolran. They are essentially 2 opposing forces that are meant to counterbalance the actions of each other. That is probably the true duty of the one with the King's star. The existence of Jin Buyeon is due to the incomplete job of Seo Gyeong though her existence also shows that Seo Gyeong succeeded in 'saving' Seolran. Thus, with the birth of Buyeon, a new King's star was born to complete the job that Seo Gyeong could not and act as a balance to the chaos that would result from the appearance of the ice stone once again.
Thus, not only were Jin Seolran and Seo Gyeong not fated to be together, neither are Jang Uk and Buyeon meant to be together. This means that season 1 of AoS is likely to end with Buyeon's soul dying along with the ice stone, thus completing the duty of the King's Star and Naksu effectively takes over the body of Buyeon most likely with her own blessings.
Jin Buyeon also seems to be or have awakened her Jin Seolran persona as shown during the interaction between child Buyeon and adult Buyeon with Naksu in the ice stone. There are key differences in how Buyeon has been depicted previously and the more cold and aloof way she is depicted as in the latest episode as an adult. Thus we can conclude that this Buyeon is essentially Jin Seolran having recovered her memories and character from her past incarnation.

I am going to go ahead and guess that it will be either an illusion created by the ice stone or Jin Bu Yeon for Naksu or its just a dream of either Naksu's or Jang Uk's.

They mentioned that the ice stone does not have a concrete form. I wonder if that might play a role in bringing Go Yoon Jung back if Naksu's real body was indeed burned to ashes.

It could just mean that the queen and the king were not a happy couple and thus the crown prince was not loved by the queen. The king probably forced the queen to marry him so that there would be a magician in his line of descendants. Thus when the crown prince mentions that people always thought that the queen wasn't his biological mother was due to the strained relationship he had with the queen throughout his childhood (aka a non-loving mother). Thats why he compares his relationship with her akin to Jang Uk and Jang Gangs in which people suspect their biological relation.

You are forgetting. The queen is from the Seo family, making the crown prince Seo Yul's cousin by biological relations. He is saying that the queen is not his biological mother because the one in the body is not his mother. This is why he always refers to Seo Yul as his cousin. If the queen was not his biological mother, he and Seo Yul would not be related.

I'm pretty sure Jin Bu Yeon is her reincarnation. So it wouldn't be a surprise if her memories of her previous life were unlocked later in her life.

No she isn't. If she was she wouldn't have needed to use a soul ejector in episode 1.