What is NK's deal?

The most confusing and yet most intriguing character is NK out of the whole show.

He rejected the proposal when Shraddha brought it to him so he is rankled that his father accepted the same girl. He is a mean person with a colonial mindset on how the wealthy need to be treated and is generously fed by Sandhya on this front. He feels humiliated that Shraddha succeeded in her quest of placing her daughter in his home and so wants to avenge this by making Shraddha as miserable as possible.