This series is good. Like, really good. 8/10. Not quite top 20 manga like the ranking suggests, but arguably top 50 and certainly top 100. Amazing story, characters, atmosphere, and romance. However, before I glaze it, I need to give 2 complaints. 1st Complaint: The Flashbacks. This series features A LOT of flashbacks. Funnily enough, the issue with these flashbacks isn't that they're repetitive or poorly written, but more often than not they completely slash up the pacing of the story. The way the story is paced, we are given essentially the cliff notes on who and what the characters are early on. As itcontinues, the main characters wander from place to place, encountering issues to solve. Usually, resolving these issues triggers a flashback that expands on how they got to that point. The issue is, these flashbacks are so detailed and have so much story, more often than not when the flashback ends you have completely forgotten what was happening and have to refresh yourself. If that only happened once it would be fine, but it happened all of 6 or 7 times for me and got really annoying. It is by far the biggest issue with this series.
2nd Complaint: The Epilogue stories.
This is definitely a more personal complaint of mine. Once the main story is concluded, there are a series of epilogue stories that are essentially like side quests. They aren't bad, just a noticeable downgrade from the start, and there are like 30-40 chapters worth of them, so they definitely overstay their welcome. Also, there was one specific scene between two characters involving the hilt of a sword that I thought was pretty uncomfortable and definitely felt like the the author was just feeling really horny one day, but there are people who will like that and they are married by that point so I can't really criticize it too much.

Ok, now for the good stuff. I'll keep it brief to avoid spoilers, because the twists in this story go crazy.
The Story:
Holy hell, this is one multilayered and complicated story. It is full of betrayal, political intrigue, and spans over years worth of conflicts. I don't want to risk spoiling it, but if I had to compare it to something I would probably say it is similar to Game of Thrones, only Chinese and with a more central storytelling process and a far less serious protagonist. And more magic. A lot more magic
The Characters:
They're great. Really great. They are almost all slow burn characters; you rarely know much about a character just from their first meeting; they are heavily fleshed out over several arcs, and this includes the main characters. This means you will only get more and more attached to a character as the story goes on. There characterization is all really consistent. Even if a character does something dumb, it almost always feels like it is something they would do. The romance is really good as well. I should probably mention that is is a yaoi series; the main characters are in love with each other, and a lot of the other dudes act really fruity, even if they are straight. This series is absolutely made to cater to the female gaze. However, that detracts nothing from the characters or story, as they are written well enough that you forget this is supposed to be appealing to a specific audience because you are so engrossed in the story. And the romance is actually really well written. It's not perfect, there are a couple scenes where characters are drunk that lead to some interactions of dubious consent, but 90% of interactions between the main pair feel really good, and I would probably say this is the story with the best written gay couple I have read (ironic, considering this is a Chinese series, and China ain't exactly a very progressive country) and one of the better romantic couples in general. Overall, the characters are just really good all the way around. They definitely take some warming up to, but once the series gets going you will really enjoy you time with them

So yeah. If that sounds interesting, definitely give it a shot, it is worth your time.