The last arch is cruel.
So many things I am skipping to spoil here, like how ML's elder brother ends...
The last part is about MC believing that foreign Princess and taking her in the Wangfu to form an alliance & try to take everyone else down (Tianyi, that other country's royals & Xiao Yan).
Let's Say that Zhonghua twists the plan and decides to leave Ouyang Nuan in the darks so she trully believes that her husband has fallen for the Princess.
He honestly deserves all the pain he's going through after he's taken down that Princess's country.
MC's cousin succesfully kills Xiao Yan.
I am not sure if she trully infests him with a sexual disease or if she just messes with his head while he's been infected with smallpox. She tells him that the courtesan that looks like MC and he took in a favored a lot, was the one to infect him.
She uses this excuse to get rid of a lot of people in the Wangfu. Since she has long not been favored, she is safe.
Getting back to ML... he started a play with that Princess and trully make MC believe their plan had become true (and not a fake ababdonment of wife),because Zhonghua dared to actually neglect her to the point she fell ill & after giving birth (alone) she sort of "dies". I think that someone used the oportunity of her difficoult labour & that the doctor had to reaninate the child to stab her with a poisoned needle.
Before all that, when MC decides to confront ML and ask him if he trully fell for the Princess, he says that he has. So she leaves him and tells him she doesn't want to see him anymore.
She stays with her adoptive Princess mother. Zhonghua leaves to battle, MC's brother too. Meanwhile Xiao Yan dies.
She has a dificult childbirth & when Zhonghua's returns (anxious to clear the misunderstanding, as if it was that easy...), she is already in a sort of death state that apparently has no cure.
He is just told that she died. He refuses to accept the reality, he doesn't even goes to see their child. He also falls ill.
It serves him right. Honestly, when MC started to feel neglected and sense ML had switched to the Princess, even though as readers we are left knowing it isn't true, I was really pissed. He betrayed her by not trusting her enough to get along with a play that was her idea on the first place!
I am glad that when she left & MC still tried to see her, she ignored him day by day and when she couldn't avoid him, she let him know that he had betrayed her & humilliated her.
ML is an idiot, unkowingly causing her a similar demise to the first life. Even though the situations were different, at the end she was abandoned in both lifetimes. The angst they go through is huge, but ML deserves it for not believing in his wife's skills.
Then, when Lin Yuanxin ends Xiao Yan so easily, it even makes the ML unnecessary drama more stupid.
ML tries to reanimate her, going to Tianyi's country to find a witch doctor, but everything is a trap. He gets blinded by a poison & Nuan gets kidnapped by Tianyi.
She is currently an amnesic hostage, as that witch doctor wiped her memory as Tianyi's command, however she can still sense she is repulsed by his touch & that he is liying to her.