Shantanu's character turned off people the way he was introduced as a stalker in the middle of that honeymoon. They they changed him to be brother of Dev which was a good story as they could have shown Vaishali's issues/narrowmindedness. They could also have shown how Shantanu in his resentment and ambition was trying to snatch things precious to Dev - his RP legacy and Radhika. Hiten also had very good chemistry with Rubina and Avinash and their characters were interesting. But they botched it up by killing Dev and making Shantanu his killer.
They also left Vikram's character in the middle because of their obsession with Amma's character and desire to have Vishaka as Barkha type character. CB creatives ruined their tracks in CB1 once they made Amma the artificial important character and did the same in CB2 when they made Barkha the same way. Then Vishaka's character was ruined in CB1 and asur, Madhavi were two irritating characters.Abhay's track had started to be good, but then again they wanted Barkha type characters. Hence Abhay was dumbed down suddenly and Kanika/Katyani were turned into these artificially important characters.I fail to understand why CB creatives have done that again and again where all the interesting characters were sidelined or killed or removed whereas annoying characters were given a lot of screen space and turned into leads. They are the ones who ruined both CB1 and CB2. Instead they blamed viewers for turning away from the show.