In Sat's epi the doc tells after her repeated injury in the same place Durga has a clot( I understood it as the clot was not there, it was because of the fall she suffered in the same place clot was formed. Correct me if I am wrong here) and if not removed surgically it can cost her life. Even for surgery there is a chance of failure and she can die.
I had always maintained from beginning that the 2 names given to the heroine Nithya/Durga talks about the constructive and destructive forces. Just like Durga tells to Dev Nithya was so positive, so lively and Durga is full of hatred and Revenge and hence she cannot be Nithya anymore , but Durga only as she doesn't have any more positivity left in her. Even her choice to go ahead with her revenge plan is because she is expecting death post surgery and wants to finish of the task she had taken.
In other words Nithya stands for life and Durga for death. Currently as far as she is concerned if she is able to make Shaurya confess the crime her task is done and she can go as justice will be served to Payal.
But that is not the truth. Durga cannot die just like that. Who will look after Payal if something happens. She has a huge responsibility of rebuilding Payal's life. Helping her complete education, make her stand on her feet etc etc.. Her duty as a sister is incomplete without this. It is not Payal ko Dev sambhalenga and go. That is running away from responsibility.
Now coming to Dev. This man loves her, loves her a lot and cares for her a lot. He respects her decisions and give her space. And the fact is that she loves him too but does not want to accept it. And if she goes without even telling him once what she feels about him, Dev as a person will never be able to forgive himself in this life for that indecision of not coming from US listening to his mom. If she dies she will be pushing him into a life of guilty conscious till his death and that means in a way he will be living but will not have life with him. Dev doesn't deserve that. He is entitled to a life with the woman he loves who also actually loves him.
To ensure she is able to do the duty of a sister completely and stand by the man who loves her so that he reaches new heights Nithya has to be back. Durga has to accept her identity as Nithya and choose life before she goes for surgery.
And I am keenly looking into how the CVs are finally making her choose life. Because that is the only way she can come back.