About the whole prophecy that one sister was suppossed to destroy the other. My friend and I have a theory, that the prophecy did not actually refer to Nadia and Syd, but to Irina and Ylena, especially since that is what happened on the show. Irina killed Ylena. Back in season 1 they thought that the prophecy had to do with Irina anyway. That' show they figured out that she was alive. It was Irina who later said it was Sydney not herself. Anyway, just a thought.