OK, so I never write a review about any drama I have seen so far but L&R turns out to be the exception in many of my never to-do list.
first of all, GREAT CHOICE of actor and actress, Cheng Yi and Crystal Yuan were the best possible match for their characters, they essentially brought the characters to life and I will forever remember Yu Sifeng and Xuanji, especially my darling Sifeng!!! seriously I fell in love with him from the first second of his appearance in the drama till the last second of the end and it had nothing to do with the fact that I already love Cheng Yi since we all know even if an actor is brilliant, it doesn't necessarily mean that the character he will play would be liked or not, but I LOVED Sifeng as much as I loved Cheng Yi and found myself smile and cry with him the entire time of the drama. He took the selfless lover to another level and I have never seen anyone else sacrifices anything and I MEAN anything and everything for his love every time and in every lifetime! he took the meaning of love to another level and I loved that he showed strong ML doesn't mean he isn't vulnerable or doesn't need protection! Sifeng and Xuanji completed each other in a way that you couldn't possibly see one without the void of the other.

This series checked all the main points necessary to be the perfect drama with xianxia/wuxia concept:

-great acting of ML & FL
-strong female lead (without the often stupid/dumb trait in female leads of other similar dramas)
-strong male lead that actually has vulnerabilities and feelings(no cold unfeeling bastard exist here)
-protective FL (it is a fact that in most dramas ML has a protective trait, but you can't see this trait often in FLs)
the FL was capable and protective whenever it concerned the ML in any situation, and I truly enjoyed that in drama.
-actually selfless and caring ML (without the often arrogance and overbearing types in AGAIN similar dramas)
-actual storyline and without getting messy and out of order in the second half of the drama
-unexpected plot (even till the last second I couldn't guess the ending, and I love to NOT KNOW what to expect)
- exceptionally perfect CGI! I enjoyed it a lot
-perfectly related music (some scenes in the drama I had to rewatch just because of the songs!)
- No unnecessary plot hole or loose ends
-out of chart chemistry between the main couple!! you could feel the love between them even when one of the main leads wasn't even aware of it!
-the BL concept was gold!!! they conveyed it perfectly between Teng She & Qing Long, Bailin & Luo Hou Ji Du, and even the sort time of Luo Hou Ji Du & Sifeng (although it was not BL but way more complex but anyhow it was short but perfect)
- SPOILER--------- HAPPY ENDING ---------
what I hate the most is that the main couple goes through 10 levels of hell and in the end one of them or both, have the fate of death or maybe worst!!!
fortunately, even though my heart bleeds for Sifeng the entire time - I mean ... you literally die because of/by the hands of the one you love for 9 times(?????) and still choose to love her selflessly and without blaming her even for a second for all the torture and pain you went through??? excuse me, are you sure you are not a Saint??? - still every character got what they deserved.

AS for weak points(not really weak more likely sad point):

-the easy manipulation on FL's side (although if I really put myself in her place, every time she tries to understand Sifeng or take his side, he would always do something unexpected to give the opportunity to others to easily manipulate her)
- miscommunication or better said no communication at all on ML's side (I mean Sifeng already knows that she lacks the 6 senses and therefore easily swayed by the words of the people she trusts and even when she gains them, she still doesn't understand all of the feelings half of the time, yet he still won't explain things better to her! he could have given a better explain or tell her his intentions instead of putting both of them through hell)
- Linglong's character should be a complex and traumatized character that makes you sympathize with her pain but instead, I was annoyed by her most of the time, the actress couldn't pull off the truly traumatized feeling well.
- the said 'righteous sect' was anything but righteous! the Irony!!! I liked the demon clan more! at least they didn't hide their evil deeds.
-If only Crystal could cry as her voice dubbed was like crying but I couldn't see a single tear in her eyes... anyhow she conveyed all the other feelings pretty well so I could look away for her lack of skill in crying.
-wish Si Feng spit out less blood
-Xiao Yin Hua was unnecessary and annoying, better keep her as snake, like in novel

but still although there were weak points (which drama is completely perfect?) I rewatched the drama for 5 times (yes, It is true) and still have to force myself to not watch it again because nothing can replace it for me and it is my first c-drama ever that I rated 10 because it had everything I wanted and needed in a drama and I love Cheng Yi, Yu Sifeng, Xuanji, Crystal and all the other characters to bring such an amazing drama to life