I'm only 7 episodes in but my initial impressions have been nothing but great.
The storyline is intriguing and mysterious, the plot doesn't meander and keeps a steady pace, and the cast is stellar.
The chemistry between Si Teng & Qin Fang is thick, thick, thick. I love watching their energy bounce off the other, and I can't wait to see how their relationship develops. For now, they're still in a master/servant (more or less) type relationship and they're building trust and rapport. Qin Fang is beginning to see Si Teng's many layers, and Si Teng is slowly understanding that Qin Fang is different than other modern men.

This is the 2nd drama I've watched with Vin Zhang. The first was Eternal Love and I instantly fell in love with his broody role as the Ghost Realms 2nd prince, Li Jing. He spent the majority of the show nearly despondent, lovesick, and angry, and I ate every second of it. Watching his character, Qin Fang, in this series has been SO FUN. His expressions are so versatile and he's got great comedic timing and control over his facial expressions and physical body language. I look forward to every moment he is on screen, especially when interacting with Si Teng (who is equally as impressive).

So far, so good! Having a lot of fun with this drama.
Side note: OST and CGI are actually really great so far. I've been used to very bad CGI from my last few Chinese shows (Eternal Love, Ashes of Love, and The Untamed. All of which are fantastic shows but very poorly lacking in CGI).

Episode 10 update:
I loveeee the shift in their relationship that I am seeing.

Episode 11 update:
Yessss!! I'm SO happy Rattan didn't go the drawn-out misunderstanding route! When they were reunited after her incident in the cave, I was worried they'd throw in the misunderstanding between Si Teng and Qin Fang over her seeing him with Yin Deng. It started out that way and she very cruelly pushed him away (aw, she was hurt!), but he TURNED AROUND and went back to explain himself! I love it. Oh my gosh, was that a wonderfully mature breath of fresh air.

Episode 24 update:
I.....didn't like the scene where Qin Fang fell. I know it was essential to the story, but the choreography of that entire sequence was really unrealistic and....weirdly unemotional? From the moment I saw him dangling off the bridge (with a giant bundle of balloons somehow still in his hand?) I felt disconnected from the scene because of how much it pulled me out of my suspension of disbelief. He fell like 3 stories onto the concrete ground and yet was so cleanly and perfectly prone in his position on the ground with the tiniest bit of blood beneath his head. I don't think anything would have been wrong with showing a bit more gore (more blood, more damage to his body, more sprawled position). Everyone on the scene was too calm, no one ran to help him- they all just stood there in a weird wide circle around Qin Fang and Si Teng while she showed very unremarkable sadness. I wanted..more? Like, it wasn't visceral enough or sad enough and it all seemed like it was happening slowly underwater. Then, not even a full 24hrs later, he's discharged to his house without an on-call nurse or any life-saving equipment (like a breathing apparatus or an IV) when they've just mentioned he's going to die soon and suffers fractures throughout his entire body? Really, y'all? I can handle a woman who shoots rattans out of her fingertips, but please don't play me for a fool with simple physiology.

Episode 30 update:
I'm overall a huge fan of this series. The ending was bittersweet and beautiful.