UrsusArctos: Ambivalence is the pyschological term that refers to the tendency of having contradictory positive and negative thoughts and feelings about the same person, object or issue, more on it here (Don't worry, it's easy to read once you get past all the references). It could be a reference to Toji's own ambivalence about being made the pilot of Eva-03, or Shinji's own ambivalent feelings about wanting to save the doomed pilot (whom he doesn't know is Toji) and not wanting to hurt them at the same time.
