Movies like Ekkadiki Pothavu Chinnavada

Arjun(Nikhil) is a visual effect supervisor with a bad love failure. One fine day, he takes his friend(Vennela Kishore) for treatment as the latter is possessed by an evil spirit. There he meets Nithya(Hebah Patel) and falls in love with her. The twist in the tale arises when Arjun comes to know that Hebah is also possessed and someone inside her body is making her do all these things. Things become ever worst for Arjun when yet another character called Amala(Nanditha Swetha) approaches him as the one who is behind all this. What is all this confusion ? Who is this Amala ? Why is she behind Arjun ? Is there a back story behind all this ?