On your request I will right my analysis on Nivren :)
Well a person with some kind of personality disorder (not split personality etc,). He is a guy with lack of love from childhood and because of that is having a problem with bonding when it comes to human relationsships. If we see Viren from the beginning, he is there for everyone, help, jokes around etc. BUT
Everyone feels themselves special because he can make them feel like that. Like he is a part of their lives, but he is not. His every relationship is superficiel. He is like a person who has been hurt so much that he has made a promise to himself that he will NOT LET ANYONE come near him... No nearness = no pain
He meets a girl who is all janooni like himself. Never thinks about herself and always thinking about others. If we see the clips of Nivren before their identity is revealed, he has deep respect for her and admires her. This is way he, after disclosure of the identities tought that "How can this girl do harm to my family."
She always went away from him while every one else wants him to be part of the family. Reverse psychology played a huge part here. He got more and more attracted until he gets to know that she loves Sid and vice versa. Old memories etc. comes up and he wants to take his revenge.
Personally I believe that confrontation of Sid-Nivi and childhood Sid-Viren matters are connected somehow.
He actually treated the whole family good until the marriage confrontation. NO ONE supported him at that moment, even BS will have been against it if he was well. Now once again, history repeats itself. CC wants to send him back, VD is understanding, but helpless like she was in the past. If u see Viren when he yells at Sid when Sid yells at Nivi. The hatred we see in Viren's eyes at that moment, that was the intro to what is happening now. He did manipulate Nivi to get married to him, but all his arguments makes sense even today.
Viren does not know what love is. He is good at making people believe what love is and he cares for them etc., but he has hard time getting it digest. How can someone love me? The question MUST have arised in his head. That is why everytime Nivi has said anything which indicated care, he had think about it (scene 89 from Navz channel) etc. A part of him is believing in her love, but the other part is resistent, because he is scared like hell. What is the heart gets broken again?
He is using Nivi to get the revenge because how can he else get it? CC is already saying whatever she can to taunt VD and Sid, YD & BS loves him too much so every mistake of his will be forgiven. So things have to be complicated and the person to accuse has to be Nivi. Because EVERYONE knows about their past so if Nivi says Sid is culprit, everyone will believe her.
He is enjoying his life with Nivi, the small progress which he is seeing in her. He knows if it was not for all that which has happend, she wouldn't have fallen in love with him. Nivi was satisfied with the role of being Mrs. Viren Sood, in which her duties was to take care of DD, Sid and rest of the household. And he wanted to show her the reality of these people too, whom she care so much about. And there we see that he managed to do so.
Sid doesn't stand up for her. VD as usual helpless. DD is suspecious, JAAL and YD as they always have been.
Eik teer se do shikar. 1) Revenge from Sid & Nivi's realisation of HOW HUMAN BEINGS ARE!
Today we get to know that VD have kept his old stuff, but no one talk about the past and that's a haunt for him. He wants to talk about it, but no one is interested. So he closes the door once again. See at the dining table where he wants to discuss things, no one bothered about it. Next day Nivi says I want to know YOU better. Bad timing I would say...
He tried to commit suicide I am sure it was probarly in his early teenage years...
Last but at least, he loves to hurt himself. He is so careless about his wound, because 1) his victory sign og 2) it gives him relief... He is close to his destination and wants the pain to remind him about it all the time. Basically Viren is self-destructive. And see the number 3 scene from Navz channel, where Nivi says to him "itni nafrat karna theek nahin, doosroon ka kuch nahin jata, chot apne dil ko lagti hai." Unknowingly she read VIREN SOOD that day 100 %. She reached to the core and and both aren't aware of it...
I just have to clarify here that I only saw the series from Viren's entry...
A simple girl who have faced too much sorrows in her life. Mother was depressed and commited suicide and father never stood up for himself or others. It ends with that she closes the doors to herself and doesn't let anyone come inside. Only person she took her inspiriation from was her grandmother, but she lived under her fathers wing all her life thinking that she is weak and isn't allowed to be "happy" etc. She was shy, and they let her be shy...
Sid was her childhood friend and when he remembered the childhood incidents etc. the friendship could start there where it ended. She fall in love with the first man she met in her young age and enjoyed it as she should have.
She felt that Sid was the only one who could understand her because she have lost her mother and he has lost his father. This sorrow will keep them together and this was the BASIS of their love.
Sorrow will either make us strong or weak. Both had the same dream regarding their families. So when Jawahar accused Keshav, both took the same stand and ended with separation. This was expected with two human beings, when they are ALIKE, they tend to make same decisions with same results.
Nivi was the strong one and took a stand regarding Sid until Divya came in the picture. She had to sacrifice herself for her. But before she reached to that point she met this guy, Viren Sood, who had attitude & didn't care about her and yet he did. So slowly with Viren she learns to fight back, demand things and get results. He helped her realise that no matter what, never give up. He stood by her at the weeding confrontation where she for the first time saw the contrast between Sid and Viren.
Shock of her life, but that is life. But she was blind regarding DD and wanted to sacrifice. Here I have to go back to Viren's dialogue from the entry promo: "Sorry aap ke sapnoon ko toot gaye umeed hai k aap ki aankhen khul jayengi."
Which they apparently didn't. Yes Nivi wants to marry any random guy so Sid could get married to Divya. Here do I see the naive Nivi. She doesn't things properly. she just thinks that things will go her way. Well will that person might have given her that much of space as Viren have done? She had been more miserable...
Viren is her thinking-tank. He makes her to reflect on things and she is a very fast learner. she trust Viren now, because she is now used to his way of being him self. In the beginning, she was nervous and scared because she doesn't knew viren at all. He gave her the space she wanted, but at the same time she cherished that he showed so much love for her all the time.
Viren Sood's existence in her life made sure that the new Nivi (who had vowed that she will never look back and will become something) got the boosts required to live up the vows. And till today, we have only been confirmed in that Nivi character is getting stronger day by day. She is loving her new self. Actually one can say that Viren have taught Nivi to love and respect herself.
So Nivi is getting cured from her weakness and getting stronger day by day and this is what Viren unknowingly have done to Nivi, which she is realising.
Her love was for Sid a little more than a crush, but her love for Viren is a woman's love. This type of love only happens once a lifetime and this is what has happend to Nivi.
Long post sorry for that and I have to say thx for appreciating my views and at last but not at least, thx to Navz for her channel which I keep refering too