The horror genre in India is mostly horror comedy or an emotional sob-story that the ghost was somehow wronged in the past and is waiting to exact revenge. Almost all 'horror' movies have to have a 'hero' who saves the day, and it's OK if the plot takes a backseat. No issues with this, but it's been overdone and badly so. Only a handful of movies have had something original and, very rarely, do you get a film in which 'Evil is just evil. No reason needed.' Very rarely.
A story that you may not have seen in other movies before, with the plot taking center stage. I didn't know anything about the actors, so to me, it felt like they were regular-day people, and I wonder if that helped the plot hit better because a regular-day guy in the plot is the 'evil' and you really feel what the family feels - "Him!? Why us? Why's he randomly doing this? He was just a regular guy."
Awesome unique plot, followed by some phenomenal acting by Janki Bodiwala as the girl possessed and by the Evil (not as menacing but did what was required) and the supporting cast. The family characters are written well enough that you care for them and flinch every time they're hurt in the film. Acting overall by everybody - great job!
The production value nothing mind-blowing, but good. Sound design, nothing mind-blowing, but good. In fact, you'd expect horror films to dial up the sound to build the intensity and I don't remember that in Vash. The silence added to the creeps
The screenplay wins in this film - the story, the characters, the ending, everything written just enough to drive the plot. No nonsense.