I'll start by saying that the show is unbingewatchable. An hour and a half for an episode was really a lot to handle for me, so be patient and take your time.

The story itself is really interesting. Nothing new or original, but still good. The storytelling technique was really articulated and helped making the show interesting. In particular I loved those scenes were two characters were about to meet, but missed each other for only a handful of seconds. It made me pay attention to what was happening without giving me any clue where the story was heading to.
The actors were all really talented. A special mention goes to the female lead who managed not only to play two characters at once, but also to keep them consistent when the two leads switched roles. Interpreting a character is hard, interpreting a second character on top of that is extremely hard, but playing a character who is pretending to be the second character you're playing and viceversa is pure talent. That said, there were some actors that probably could have played their characters better (*cough cough* Suea *cough cough*), but they were secondary characters.

Now there were a few very important things I didn't like. Some characters really seemed immortal (*cough cough* Diew *cough cough*) and that was just boring. I understand some characters need to stay alive, but don't put them in life-threatening situations so often. They may survive once or twice, but at the millionth time it gets absurd.
Also, Nok is supposed to have been raised her whole life in France and yet I cringed so hard the few times she spoke French. I understand the actress is not required to know French, but if that's the case, don't make her speak French. Nok sounded like someone who's never even set foot in France.
The OST was bad, but that's nothing too serious. What I think is the biggest problem of this show is the production value. I can't believe this was produced recently, it looked like a late 90's/ early 00's series. The audio was also quite poor for 2021 standards. And I don't even want to talk about special effects: every fight looked pitiful with those fake shot wounds and blood spills. I don't enjoy action scenes too much, but these were seriously bad.

All in all, the show itself has a really big potential, it's just a shame the production is so poor. I'd still recommend it, just ignore all the pitiful killings and fightings.