ML is sect's leader also genius doctor that only visit few people each year and his price is quiet expensive.

FL was ML's master in previous life and now in her current life she doesn't remember her past and opposite of her previous life, She have fragile and sick body now.

ML with one condition helps her to become overcome her illness: She should be his student.

ML is demonic immortal that want to conquer the world but cus of FL he find something more special tp protect but lost it and for that he waited 20 years and want to make pacefull world for her

Both are sad love story about love and people who seek happiness with being together but fate don't approve it...

ML is demonic immortal
Fl wants to stop her from the bad things he is going to do
ML have sad backstory and painful life
ML is prince and sacrifice so much for FL

When I read the novel it felt like I'm reading straight version of Untamed.
ML is poker face who hate FL cus she is so flirtatious with him and not him with every boy around. Her personality is like wei wuxian. Like she is his twin sister or his woman version XD
FL loves to drink and fool around. She wanted to protect everyone but they killed her to have her powers.
ML waited 20 years to meet her again and for her sacrificed so much just to be with her again.

Both are xianxia
Both are about love between master and his student
ML is cold, strong, sly and cunning, most of the time poker face
FL is smart and little by little become strong

From same director and screen writer
ML sacrifice so much cus of Fl fortunately FL is not naive like someone we know...
Forbidden love with good amount of angst and sweat moments.
ML is demonic immortal and he is kinda gray and even sometime he can be black...

From same novel writer
Strong ML, Strong FL
Let's say both have writers same writing style and it's more focosed in Main CP's story than extra thing.
ML in both is prince

Both are:
+Female-centric
+Reverse Harem (Multiple MLs)

ML in TMWTCR is King who want to gather power so can make peaceful life in country especially to FL. His personality is kinda like CX.
SML is a villain with two different personality, Which he use his different identities to trick others and run his plans. His personality and love story is kinda like XL.
TML is FL's bodyguard with unspoken feeling who is always around FL.

Both are:
+Female-centric
+Reverse Harem (Multiple MLs)

ML in TMWTCR is King who want to gather power so can make peaceful life in country especially to FL. His personality is kinda like CX.
SML is a villain with two different personality, Which he use his different identities to trick others and run his plans. His personality and love story is kinda like XL.
TML is FL's bodyguard with unspoken feeling who is always around FL.

From same author in same universe.
Dashing Youth is prequel of The blood of youth and all of these dramas are in same universe.

Both dramas are in same universe.
Tales of dark river is spin off of blood of youth and tells a story about assassin organization that had some parts in original story.