Realmlist updating failed wow
For this quest you need to kill 15 Black Broodlings, 10 Black Dragonspawn, 4 Black Wyrmkin and 1 Black Drake, which can be found throughout the Burning Steppes.After you complete the quest he gives you another quest called The True Masters where you have to deliver a letter to Magistrate Solomon in Lakeshire.
Another theory is that most people in the raid are not on her threat list since a lot of raid leaders want people to spread out and do nothing because most of the time she is not in range.When you enter there Lady Katrana Prestor turns into Lady Onyxia and spawns around 5 elite guards.Unless you are a ranged class i advise you stay away after you finish The Great Masquerade you get a quest called The Dragons Eye.You take the item he gives you and bring it to Haleh who is in a cave to the south/middle of the Winterspring map. So either take a group, or get naked and start corpse running.At the back of the cave is a blue glowy thing on the ground. After you talk to him you get another quest to kill General Drakkisath who is located in Upper Blackrock Spire (UBRS) and carries the blood you need for the quest.
My guild at the moment kills her in about 3-4mins tops.