Kadaeux wrote:No, Deathwing is not what makes the Dark Angels special. Ravenwing is. Only the White Scars have something even remotely comparable to it.
To be even more accurate: It isn't the terminator armor that makes deathwing special it is knowledge of, and mission to hunt, the Fallen Angels. Without that they are just another 1st company. But those guys know secrets. Dangerous secrets.
I think there are several things unique about the Dark Angels, and the Ravenwing is just the most obvious. All of their uniqueness is linked to the Fallen Angels though. From the differences in their librarians and chaplains, to the purpose of the Deathwing and the Ravenwing. Even their interactions with other chapters and other groups in the Imperium government is governed by the fact that they have the Fallen as a dark secret. They will abandon any ally to hunt the fallen, and have done so many times before in the lore. Hunting the Fallen is what defines the chapter, and the Ravenwing is tasked with that hunt.
This is all very true, but I was referring more to doctrinal layout of the Chapter from a tactical/strategic point.
Other than some unique equipment (And most chapters have their own of sorts) the Chapter layout is mostly identical.
The Dark Angels however have the Ravenwing 2nd Company which diverges greatly.
The Black Templars don't have a "Scout Company" instead blending the neophytes in with normal squads.
The Blood Angels have Death Company
From astartes combat doctrine, it's the Ravenwing that is unique