This is adopted from a proper BL novel  but is not BL and though they do a good job with taking the story in a non-BL direction, some flavor is still missing in my opinion.
The novel is so much more convincing when it comes to the main relationship, the Beloved Enemies because in it Gu Qing Pei is actually gay and is extremely attractive to other gay men that surround him (His foxy cunning is so alluring). Yuan Yang is young and brash and initially has non consensual sex with GQP, but the passion in their relationship gradually is very convincing. But that is the novel.
This Drama is a separate beast altogether. Though the main relationship remains explosive with unresolved sexual tension that is very palpable, in absence of actual sex a real mentor and pupil relationship comes to a forefront and the progression of said relationship is very realistic. As a rule the story deals with two very different and lonely people who have no one they can trust, as they are thrust into a situation they both don't want while being chained by their temperaments and positions., And the show does very well with the options it got. I mean, I would watch it for the suiting (costumes) and visuals alone, but it also has an intriguing plot and some good arcs and a great eye-candy cast. So kudos to this. I know it's futile, but I hope that one day we will get a proper BL adaptation of this too... *sigh*