The Netherwing have a lot of history built up during the Burning Crusade, and present a curious puzzle to the dragon flights of Azeroth. Tyrygosa, a member of the blue dragonflight, traveled to Outland with Jorad Mace, a human paladin, to study the nether dragons in an attempt to discern where the flight had come from. Tyri had heard rumors that the strange dragons were descendants of Deathwing himself, but they looked nothing like any black dragon ever seen before. Players help Tyri and Jorad at the Celestial Ridge in Netherstorm to gather information about the drakes, and to establish a display of dominance to cow the dragons into submission.
After the events in Burning Crusade, Tyrygosa took some of the nether dragons with her to Northrend and showed them to Malygos, who had been driven largely insane by the near extinction of his flight at the hands of Deathwing. There was something to these nether dragons however, and whether it was their strange powers from being broiled in the Twisting Nether as whelps, or just the curiosity factor of the dragons, they did have a positive effect... sort of. Malygos began to regain his sanity -- and began to take a good look at the world around him and the sheer number of mortals flinging spells around like happy fun rocks and decided the world would be a much better place if those mortals simply ceased to be. Thus, the spark that set off the Nexus War in Wrath of the Lich King, ending in Malygos' ultimate demise.
Was this the fault of Tyrygosa, who simply sought to help her ruler, the leader of the Blue Flight? Or was it the fault of the Netherwing, who had no idea what was going on over on Azeroth, but agreed to go with Tyri? This is unknown, although supposedly there's a new manga due to come out that will follow Tyri's ongoing adventures. What can be gathered from this however is that the nether dragons themselves would not exist if Deathwing hadn't taken the eggs to Outland to begin with, so perhaps Deathwing had his ultimate revenge on the Blue Aspect after all -- even though he doesn't realize it.
In the meantime, the nether dragons had problems elsewhere. A small collection of the dragons located in the Singing Ridge in Blade's Edge were continually being harassed not only by the Mok'Nathal nearby, but also by a group of entirely too curious gnomes at the Toshley's Station outpost. While the Mok'Nathal merely viewed the drakes as pests that needed to be exterminated, the gnomes were curious as to the nether dragons properties and wanted to see if they'd be useful for medicinal purposes.
It seemed that no matter where the nether dragons settled, they were unable to find any kind of lasting peace. This was especially true for the Netherwing flight of Shadowmoon Valley. The Dragonmaw clan of orcs, well known for their prowess in capturing and subduing dragons, had come to Shadowmoon Valley under the service of Illidan Stormrage. Much like their previous attempts with the red dragonflight, the orcs, under the leadership of Zuluhed the Whacked, quickly captured the matriarch of the Netherwing, Karynaku, and use her children much as they used Alexstrasza's. Players in Burning Crusade ran into a curious NPC wandering around Shadowmoon Valley -- Mordenai, supposedly just a high elf.
Mordenai is terribly concerned about the spooked nether dragons flying above, however. Apparently the dragons won't even come down to feed, falling to their death from exhaustion rather than landing on the ground below. He asks players to place carcasses from nearby rock flayers in the fields, and wait for the drakes to come down to feed.
Thus starts the curious tale of the Netherwing flight. From there, players seek out the patriarch, Neltharaku, who is flying overhead, and listen to his tale:
Neltharaku: In the eastern reaches of the Netherwing Fields lies Dragonmaw Fortress. It is there that the cruel Dragonmaw orc clan tortures the drakes that they capture in an attempt to bend them to their will. Many have given up hope, choosing instead to do the bidding of Dragonmaw. The others... They refuse to land for fear of Dragonmaw war parties capturing them and taking them back to the fortress.
Player: But you are dragons! How could orcs do this to you?
Neltharaku: I... We are powerless. Illidan found and delivered unto the Dragonmaw their leader - Zuluhed. This orc was the one responsible for the capture and incarceration of Alexstrasza. How could we fight against such power? He captured an Aspect!
And just as easily, he took my mate.
Player: Your mate?
Neltharaku: Karynaku... She is held prisoner atop Dragonmaw fortress. I have made many attempts to free her. All have failed... You have battled these beasts before, have you not?
Player: I have battled many beasts, dragon. I will help you.
In a series of quests, players are eventually led to the conclusion of the story -- freeing Neltharaku's mate, Karynaku, and putting an end to Zuluhed once and for all. Upon completing this, Karynaku herself flies players back to Mordenai, who is revealed as the son of the two dragons -- in high elf guise of course. A happy family reunion all around, but the work is far from done.
Zuluhed may be dead, but the Dragonmaw still serve Illidan -- obediently harvesting minerals, pollen, and crystals from Netherwing Ledge, and subduing the netherwing dragons into suitable mounts and packbeasts. Mordenai has clearly had enough of the Dragonmaw, and wishes to wipe them out for good -- which is where players come in. They are asked to take a blood oath and assist the Netherwing Dragonflight in retaking their lost lands, and overthrowing the Dragomaw orcs once and for all.
While the Netherwing haven't been around very long, historically speaking, they've definitely got one thing going for them -- they're clever. Much like their father, Deathwing, they chose not to go the route of a full frontal assault on the Dragonmaw orcs, instead choosing to go a subtler route. Players are asked to infiltrate the Dragonmaw orcs and given a disguise that makes them look like nothing more than a lowly peon. By working for the Dragonmaw clan, players can help the Netherwing rip the whole operation apart from within.
This bears an almost uncanny resemblance to the attempted downfall of the Alliance on Lord Prestor's part, or the subterfuge involved with Lady Katrana Prestor, a.k.a. Onyxia, and the attempted takeover of Stormwind. While the Netherwing are an agreeable sort, nice enough when you get to know them, every once in awhile there's a hint of the black dragons they could have been.