Originally Posted by metaphysician
He could just as easily be talking about the leader/founder of the Masters of Evil. After all, self-centered psychopaths would need even *more* leadership to function as a group than the Avengers would. That implies a pretty capable alpha villain as the true threat, with the Masters as, essentially, extensions of his will.
This. There's an interview with Kevin Feige for the first movie where he mentioned something along the lines of Loki being the only villain they referred to promoting the movie because he was more important than the aliens. That being said, at this point Thanos or Korvac seem just as likely.