Before I say anything more, I just want to state that this manhwa is absolutely amazing. It's hands down one of the best I've ever read, regardless of genre and what have you. This is also one of the few BL mangas that I would recommend to those who are not fans of the genre. It's a fantastic work, and it is definitely a shame if you chose not to read this manga because of the characters' romantic interests.
The characters are definitely the driving points of any manhwa/manga, and this one is certainly no exception. The two main leads are very well fleshed-out, and their development is also very nicely done. The side characters too are also very real and wonderful to watch, with their own development to follow.
And, don't be fooled by the summary, this manhwa doesn't consist of Sehara telling Shahryar story after story in his bedchamber (though there is a story in each volume). The characters actually go out and do things that lend to their personality and ideals.
My personal favorite character development was definitely with the Sultan, Shahryar. The backstory the author gave him was, quite simply, the best I've ever seen in terms of a tragic character.
His issues with women stemming from the death of his mother, and the dissonance between his love for Fatima and his father's words (that all unfaithful women deserve to die)... It was all so heart-rending, painful, and oh so real. I also loved that Shahryar accepts the fact that his past is no excuse for what he has done, that he really has to help heal what he has broken with his own hands.
Personally, my favorite part of this healing process was when Shahryar got tricked by his brother and allowed his city to fall to the invaders. It showed that, although Shahryar had gotten better because of Sehara's help, he still had not fully let go of his past. Again, I would like the point to the realism of his struggle, as the healing process isn't something that happens immediately but gradually and painfully. (Though, truthfully, I also hated this moment too because I spent the next three volumes yelling at the screen and waiting for Shahryar and Sehara TO GET BACK TOGETHER. /rage)
This manhwa also contains the best use of anachronisms I have seen in a manhwa to date. The majority of these anachronisms take place in the stories that Sehara tells. And, speaking of these stories, there are some truly heart-breaking and beautiful ones. There were two that I absolutely loved, and one even reduced me to tears. (Anyone who has read this manhwa will know which one I'm talking about.)
Definitely something one should not judge by first impressions (whether by the cover or by the first few volumes). It gets better, without a doubt.