Baron Zemo

We have no idea what his end-game is (we have an idea, actually, but we are waiting to see more of him when Civil War arrives) and we have no idea how different he is from the comic book version. But he must add up to something – otherwise, he wouldn’t be the big bad villain of the Civil War.
We don’t have our hopes too high, though, since the first reviews of Civil War have said that this is yet another opportunity that Marvel has missed. However, those same reviews did say that he is an actual physical threat (with his sword) for both Captain America and Iron Man.
So he at least has that – oh, and we did see him, even if only in the TV spots.
