sincere about wanting Klaus dead. Remember the episode when she was have flashbacks about her family? She actually cried. I think she not only wants him dead for selfish reasons I think she wants him dead for what he did to her family. The writers are making a point about how good Katherine is at imitating Elena so I wonder if when Klaus comes to town if she will act like Elena to try and get close enough to kill him. I don't know if she is unselfish to let herself be the one sacrificed to screw up the ritual but that would be another way to do it.