Location:

Blackwing Descent is located at Blackrock Mountain which you can access through the Burning Steppes or Searing Gorge. Players that have completed Blackwing Lair will find the entrance to the instance nostalgic: it is accessed high on the Western side of Blackrock Mountain through the room where Vanilla WoW raiders first fought Nefarian.

Bosses:

Magmaw - This boss is like Ouro the sand worm if you dipped him in magma and made him spit fire. This is one of the first two bosses along with the Omnitron Defense System. You can choose which one you want to do first.

Omnitron Defense System - In this encounter you'll fight four Golems that act as the guardians of the Blackwing Descent. The fight begins with one Golem active and as the fight progresses three additional Golems will activate. Players must kill all four to proceed.

Maloriak - This boss is a dragon-humanoid hybrid. He throws vials into a cauldron which trigger special highly dangerous abilities. When pushed to 20% health he gains additional abilities and attacks relentlessly; raiders will need coordination and great execution to prevail.

Atramedes - A large flying dragon, this encounter has one of the most unusual mechanics in recent memory. Atramedes is blind and relies on sound to hunt, players will gain a 'sound bar' when they attempt this encounter and if any player's bar reaches 100 Atramedes will annihilate them quickly regardless of their gear or whether they are a tank. Players must use the gongs placed around the room to disorient and stun Atramedes and to reset their sound bar.

Chimaeron - This boss is a massive three headed Hydra. He has some bizarre abilities: as you fight him there is a robot running around the room spraying slime. This slime will make you immune to death if you have more than 10,000hp. You'll need to make smart use of this slime so your raid isn't one shot by Chimaeron's powerful AoE attacks.

Nefarian - He's back! Both Onyxia and Nefarian are back from the dead and ready to play. You'll begin the fight with a rematch against Onyxia. You'll need to quickly dispatch her before her damaging aura grows out of control. After 30 seconds Nefarian will land and must be separated from Onyxia as they have a buff they gain when in proximity to each other. Reanimated Bone Warriors will soon join the melee and you'll be dodging shadowflames, lava, and Shadowblaze which is a type of 'smart fire' reminiscent of Mimiron and Archimonde's. You'll have your hands full with this long and complicated fight.