7.
The main villain isn't really developed at all, if you can even pin that label on someone. Sure, the emperor wanted to kill everyone and absorb everything or whatever, but there was no Alderaan event like in the movies. Nothing to show that he was ruthless and evil. We were shown, and not told, and that leads to a weak character. Turning the jedi masters to the dark side was a step in this direction, but the fact that they resisted his influence and decided to be evil for themselves just makes the villain less menacing.
Companions were amazing, however. The only one that I felt was lacking was Sergeant Rusk, but all the others were pretty interesting. And I did like that turning some of your opponents to the light side was recognized towards the end of the story.
Still a better story than Sith Inquisitor, even though that villain is more personal and flushed out.