Star Wars: Rogue One - 16 Major Details Lucasfilm Just Revealed
8. Ben Mendelsohn’s Director Krennic Will Butt Heads With Vader
In lieu of Vader, the primary villain of Rogue One is Director Orson Krennic, Ben Mendelsohn's white suited Imperial in charge of the Death Star production project (better get himself set for failure). As hoped, he's described as a new type of Imperial villain, an intelligent, ruthless tactician with a real intensity, a stark departure from the alternatively cold/sniveling officers of the original films.
In fact, everything about the Imperial structure sounds very different to what we're used to from the original trilogy. Rogue One looks to be Game Of Thrones in space (Game Of Flying Senate Pods?), with everyone in the Empire scheming to acheive their own goals as much as the order's greater good. The biggest example of this is word of Krennic's hope to uproot Vader; because of the Sith's now inherent mystery, the Director finds this strange "other" a threat and wants to secure his own status next to the Emperor.
So yeah, Vader'll probably kill him.