Tuhr Altar

Sinestra, the Mother of Dragons, was the Boss of the Secret Dungeon in the Black Rock Mountain. To meet her, players were required to kill the father-child trio, specifically Ferrian, Onyxia, and Deathwing. Without that, Sinestra would not appear no matter how much effort the players put into clearing the dungeon.

The Secret Dungeon in the Black Rock Mountain was named Black Dragons' Wild Ambitions. Sinestra existed as the final Boss of the dungeon, and players only achieved a 100% dungeon clearance after they had killed her.

However, the Sinestra within the Secret Dungeon was only a Dragon Soul that had no physical form.

It made sense now why Sinestra was only a Dragon Soul left in the dungeon. Her original physical body had already been sent to the outside world by her husband Deathwing. 

The Mother of Dragons… If used properly, could Sinestra become the ultimate reason for Onyxia's breakdown?