Just my thought...I don't feel like Vihaan will be turned negative. He is a just a little spoiled because he is a little rich and the youngest.But i think he has big brother and loving family so he should have good family values and cannot be shown as a completely selfish person.
I think he is hurt with the girl's prank on him but once he does the revenge then his anger will subside and then he will feel guilty. The only thing is he does not think much of Rachana so I am not sure if i want him to be paired with her. I feel like the whole time she will be trying to change herself to win his heart and it will be too much on that innocent girl.
Maybe that is why i want Gunjan with Vihaan to break his ego down and make him a better man. Anyway, frankly i would first like the girls to focus on their lives other than all this wedding/fiances etc.