Hancock's villain??

Hey guys…..

I was wondering who is the villain in the movie hancock??
I mean hancock(will smith) is the bad guy turned hero in this movie……he is fighting against somebody….
Unlike other movies the trailers don't show who the villain is….
i mean i saw dis trailer....
Is it some other superhero?? or something other??
Lets make wild guesses……..
n do u know of any such links which have other hancock traillers???