Ayleberry

Also in episode 13 towards the end, he explains how his feelings deepened after she gave away the life saving immortal vine to someone she didn't even know (which ofc, happened to be him). Shen Xihe may have gotten GQZ's tuhlessness and knowledge, but she is still her own person. A comment below me described her as half and half.

He lived outside the capital due to his health, in a temple iirc. And GQZ was the principal wife of Prince Xin. Under such circumstances, there would have been little to none opportunities for the two of them to meet or know each other's personalities and stuff. At most he'd know from the info from the capital that she was a cold elegant noble lady.

this was given in the authors notes in the novel, and mentioned in one of the discussion posts. I don't think its a spoiler, but just in case i have put it under spoiler tag

It is not a soul swap, its more of SXH gaining GQZ's memories and experiences, someqhat like a soul merge. GQZ's soul merged with SXH sorta, so now she has memories and experiences from GQZ's life, but she is still SXH, just with extra memories and knowledge now. The two women do not have the same face. GQZ face is not shown in the drama, and Prince Xin only recognises her because of her actions and habits, which mirrored GQZ.

See you on the other side! XD

if its a so bad but so good list, you just HAVE to put in 'Master devil please don't kiss me'
its one of those ridiculous dramas which throws in every cliche and story-line ever but still manages to hook you in despite the craziness. Although, more than crazy plot twists, its the productions and CGIs that make this drama a crazy ride.
there's also a season 2 to this with the same actors, and a season three came out last year, but the actors are totally different. I didn't watch the last season, but the description itself gives you an idea season3 is the craziest in terms of plot-lines.
My personal favorite is season two which came out a little like playful kiss.