Hadronox Denied

Enter Azjol-Nerub on Heroic difficulty and clear through to the Hadronox chamber after defeating the first boss.

To clear the room of adds before engaging Hadronox, have one player aggro the elite Guardian then use a reset mechanic such as Feign Death, which despawns all adds and leaves Hadronox alone in his chamber below.

Jump down and run directly to Hadronox, pulling him the moment you arrive. He will not web the doors if engaged immediately, but will do so after being alive for a short time, so do not hesitate.

Nuke Hadronox as fast as possible. A large number of spiders will be attacking him and he heals for 10% health each time one dies from his Leach Poison, so you must kill him before those adds die. Use Bloodlust or Heroism immediately. If a Paladin is present, have them apply Judgement of Light to Hadronox, which heals the attacking adds and buys a few extra seconds before they die.

Alternatively, after killing the third crusher pack, position your tank with their left side against the spike that protrudes near the corner of the right stairway, facing where Hadronox emerges. When Hadronox rises with adds on him, taunt him away from the adds and keep him facing the stairway path. The rest of the group should move behind Hadronox to avoid cleave effects while burning him down.