Using this to their advantage, the Old Gods corrupted Deathwing as a way to make their plan 'foolproof', using one of the very Aspects destined to stop the Hour of Twilight, to instead usher it. Īman'Thul's vision of the Old Gods one day causing the Hour of Twilight, capable of potentially wiping out all life on Azeroth, was one of the reasons the Pantheon empowered Nozdormu and the other Dragon Aspects with their powers, to ultimately avert this single catastrophe, although Aman'Thul for all his vast powers was not omniscient and was unaware Neltharion would eventually be corrupted into Deathwing. When the Pale, as the Twilight's Hammer clan, arrived on Azeroth during the First War, they immediately sensed the Old Gods and realized Azeroth was the place where the prophecy would occur.

On Draenor, the Pale orcs received a prophecy of the Hour of Twilight from the void lords: a time when the shadow would envelop the universe and snuff out all life in existence. At the last sunset, the Old Gods, sealed away within the depths of the world long ago, will enact their judgment and irrevocably twist the mortal world to reflect their essence.

A very ancient prophecy speaks of the Hour of Twilight- Azeroth's final moments of existence.

Hour of twilight world of warcraft