Deathwing

The Deathwing is the Dark Angels' name for their First Company (also used by all Dark Angels successor chapters). Unlike the First Companies of Codex Astartes-compliant Chapters, the Deathwing exclusively fights in bone-white Terminator armor, and never forms power-armored Veteran Squads. They are part of the Dark Angels' Inner Circle, the secretive cabal that hunts the Fallen Angels, members of the Dark Angels Legion who (allegedly) fell to Chaos during the Horus Heresy -- in fact, the only way to join the Inner Circle (and thus become a Company Master, Librarian, or Chaplain) is to be inducted into the Deathwing.

Deathwing Terminators are not very different from Terminators available to Codex Chapters, but they tend to operate as one army, as opposed to single squads distributed among deployed forces. This is represented in-game by allowing a Dark Angels army which includes Belial, the Master of the Deathwing, to take Deathwing squads as Troops as well as Elites (allowing up to ninety-one Terminators to take the field). The "-wing" suffix has come to be used as shorthand to refer to other all-Terminator armies, like Draigowing, where Kaldor Draigo allows a Grey Knights army to take Paladin (super-Terminator) squads as Troops, or Loganwing, where Logan Grimnar (of the Space Wolves) causes Wolf Guard (which may be Terminator-armored) to count as Troops.

Update: As of the 6th Edition Codex by Jeremy Vetock (praise be his name) the Deathwing can now rape Chaos Marines. Nothing says repent like a T5 Terminator with a mace the size of a man. The regular Deathwing got some handy new rules, including a Plasma Cannon, which while not entirely useful, is awesome.Template:Marines-Codex