She is not evil at all. Evil is a very strong word.I don't think any HM is evil. They are all playing game here so they can't act like good guys or saints. They need to use strategies to survive and win. Doesnt make any one evil.I don't even think Puneet is evil
Only difference is that some HM's strategies to win is more negative and other's are less negative that is all
About karishma she has her flaws and has made mistakes. But atleast she isn't fake.She is what she is and accepts that openly. If she is selfish she accepts that. She doesn't use any type of sympathy card, fights directly with people whom she doesn't like even if she knows they have audience support. Takes all of salman's jokes and bullying of her with a smiling face.She is here to play the game and she knows it and accepts it. Doesn't try to pretend otherwise. She is not very intelligent but isn't very dumb also. She has recognized puneet's true game plan and have said it to his face twice
So yes because of the above factors she is one of the major players this season