Who will be the primary villains in Star Wars Episode vii?

After hiding in the darkest corners of the Star Wars galaxy
for thousands of years, the Dark Jedi finally have a leader,
who can bring their large numbers under one command. This
great Dark Jedi general is a military genius and the Dark
Jedi are going to have much battle success following the
tactical and strategic plans of this military mastermind.

Luke Skywalker and the other heroes of the New Republic
have to devise schemes to counter the brilliant strategies
and tactics of the Dark Jedi. It will be a war fought with
brain powers instead of pure military might. The most clever
military leader (whether it is Luke Skywalker or the Dark Jedi
commander) will ultimately achieve victory.