Karan too kind for a stranger?

Recently we seen karan buying the chaudharys house and then giving it back to them because aparently they helped his dad,but is the truth too kind to be believed,i Believe that karan is upto something and that something is revenge on swamini!,Karan may possibly be swamini buas son from the past as we recently been seeing alot about swaminis past and how she realy liked somebody that she was upto even leaving the vadhera house.