The Empire is struggling to keep their lands safe. In the Empire campaign, you fight as Stefan Von Kesil leading the imperial forces against the warhosts of the Undivided, Khorne, and Nurgle, and also hordes of Greenskinz.
You take control of Chaos Champion Thorgar the Blooded One and lead the tattered remains of the Chaos forces in a mighty war against the Empire, in order to become a near-invincible Daemon Prince. Your conquest shall continue in a series of brutal attack to cripple the Empire. But you must first choose your God. Khorne, the God of Warfare, who will help you slay your foes through excessive force, or Nurgle, the God of Filth, who will protect you from harm through pestillence while you kill and pillage...
The basic outline of the the Orc campaign, is that the Greenskinz are on a Waaagh! in search for worthy battles to fight, while the Dark Elves are marching and cutting their way through the Empire, in search for the Archmage Aurelion.