Lee Seol is the deposed crown prince who was supposed to be killed, but DanOh had saved him back then. 

Lee Seol's parents were dead and he has been chased by the royal soldiers since then and currently he is called Speck of dust. 

Lee Seol might be: 

  1. Kang San (good at martial arts, has a sword and hidden background)
  2. Yoo Ha (who's a scholar & is hidden child of his father)
  3. Shi Yeol (gambler, broke & cute behaved man)

Shi Yeol, i hope they end together.

In episode 2 he already revealed him self with the dog. 

I think Kang San is somehow related to the Shadow warrior who helped Lee Seol when he was attacked at the Head Eunuch house.

I really want Kang San to be LS. I'm pretty sure Yoo Ha is not(But it's still 2 episodes, so not 100% sure). But whoever it is I just want the girl to end up with whoever is LS. ;D . LS's character was made stiff and upright personality in his kid versions, so it's hard to think of Shi Yeol as LS. 

Or is he hiding in the annex!?

I’m curious too.  I really think it has to be one of the three.  I am leaning towards  Yoo Ha.  

Lee Seol could be neither of the three, which I would prefer tbh. I think the plot would be for longer if it wasn't one of the three and considering this has 18 eps and the three of them already have fair share of mysteries. But idk.

Also, the watchman that protected Lee Seol on ep 2 look like Yoo Ha? I mean his eyes look like his. Idk, I might be tripping. But if he has the scar on his arm, it's definitely him. I want it to be him!! 

We all know now on episode3, Kang San is the watchman.  Yoo Ha, seems to be the illegitimate son of the  Crown Prince and the courtesan lady that runs the Bo something place. My bet truly is ShiYeol, because the dogs like him and made a hint that what if one of us the Lee Seol. Also, he's name Shi Yeol close to Lee Sell. That's my intake on these drama

If I know anything about historical romcom clichés, I'm 99.9% confident that Kang San is the deposed crown prince. There are just too many tropes that align with his character. I think the personalities and looks also match well with the younger versions, and also it makes the most sense for him to be Lee Seol with all we have been shown so far.

 seonni:

If I know anything about historical romcom clichés, I'm 99.9% confident that Kang San is the deposed crown prince. There are just too many tropes that align with his character. I think the personalities and looks also match well with the younger versions, and also it makes the most sense for him to be Lee Seol with all we have been shown so far.

I don't think he is,  on episode 3, the head eunuchs already told Kang San either kill Lee Seal or put him on the throne.

 Avegay:

I don't think he is,  on episode 3, the head eunuchs already told Kang San either kill Lee Seal or put him on the throne.

That was not an order, but a demonstration of his own power, since he is the only one who can recognize him, he can either choose to denounce him for treachery to those who want him gone or confirm he is indeed the crown prince if he is to be reinstated again.

 seonni:

That was not an order, but a demonstration of his own power, since he is the only one who can recognize him, he can either choose to denounce him for treachery to those who want him gone or confirm he is indeed the crown prince if he is to be reinstated again.

On episode 4, towards the end the prince is She Yeol.

 Avegay:

On episode 4, towards the end the prince is She Yeol.

All we had was an unknown old man calling him Your Highness. There could be a thousand explanations for this that don't involve him being the deposed crown prince. We have to wait to see, but my I'm pretty sure it will be just a distraction in the end.

After watching episode 6 I think Yoo ha is the deposed crown prince and kang san as the watchman. Or Kang san can be the crown prince who's also playing the role of watchman.

I still think Shi Yeol is the Lee SeoL. Come one if people looking for you all your life and have a sword on your neck are you going to admit who you really are???

Six episodes done and I’m leaning more to Kang San as the deposed crown prince although Siyeol is kinda sus to me as well. But I think it’s really KS and him trying to guise as the watchman is part of their plan to overthrow the current king.