Devika said she is chandani becuase she saw all Nahar family there including Neel and Saloni. She wanted seal now more than anything to destroy Nahar parivar to revenge his baba and chandani's death. She thought it will be best to stay in the house and make them miserable like chandani did . Also if she is chandani then Saloni will leave Nahar and marry Neel. That ways she will have revnge on Nahar as well becos Nahar loves Saloni so much and neel will give her seal.
It is very logical and it makes sense perfectly. We cannot underestimate the person who staged the drama of being raped by some goons. druged nahar to get aditi on her side. sent ppl to get brijesh parivar in her program . Got her self entry in Nahar's heart and and his parivar by hook and crook, kidnap yug and so on. How can a manipulative person like her can call herself naive She is a pure evil worst than chandani and more capbale of casuing a disater.
