
Omg... It's the eldest bro, the Villain!!??
But how do you know it?
By the way, if the eldest brother has the grudge then it should be against the Sanghee 's father (4get his name) so why the eldest brother targets Sanghee !? Even he also helps the emperor to conspire against her!

This is all my assumption since they hid the villains identity as a dark shadow.. it feels like there's a traitor in the king's kingdom.. there's actually a hint in the part when they took a journey home and was attacked by a dragon.. and I've been thinking who could have been it is.. and to be honest.. I don't believe that the eldest brother s character will just be as plain as he is now.. I think there will be a twist and that is him being haaayy.. one of the enemies

No I don't think it's her older brother. He would have known since the beginning that the actions of Sanghee's father are just because he cares about her, and not some political thingy.
But the Emperor was completely unable to even imagine that his actions were because he cares for his daughter until the end of season 3.
I got this bad feeling that the "dark shadow" with the Emperor's side is her eldest brother (forgot the name).
I don't want to entertain this bad feeling but it bothers me.
Like he's so perfect and all. Sanghee doesn't even dislike him a little bit.. unlike the 2nd and 3rd brother with flaws but the story clearly shows they have sister complex(hahaha).
It feels like his true evil intentions will show in the end and will bring great danger to Sanghee cuz she trust him..
Like he becomes bad because even he is the eldest he isn't actually the next in throne (it was the 2nd prince right, I clearly remembered thier father offering it to him In the middle of the story) one thing more.. the older brother was actually a prisoner in the Emperor's kingdom like a sacrifice for peace something like that..
Hmnn... I hope this is all just me... And nothing like this will actually happen..