The Obsidian SanctumIntroduced in Wrath of the Lich King
More than ten thousand years ago, the black Dragon Aspect, Neltharion, began a quest to reign supreme over his fellow dragons and thereby dominate Azeroth. Before Deathwing -- as Neltharion came to be known -- could achieve his goal, the other Aspects drove him into hiding, but the rest of the black dragonflight continued his foul work. Hated and hunted for its evil deeds, the black flight dwindled, and at first Deathwing schemed to bolster its ranks. In time, however, his agents began experimenting with other dragonflights to create a new and mightier breed of dragon.
The resulting experiments gave rise to a powerful and terrifying new breed: the twilight dragons. These malefic dragons were believed to be destroyed after an attack on Grim Batol, but a new clutch of twilight eggs was recently discovered within the Obsidian Sanctum, the black dragonflight's domain in the Chamber of the Aspects. Now Azeroth's heroes must destroy the brood once and for all and prevent the dark future that has been set into motion.