The Demon Soul... Where to begin
Shaped like a golden disk, the Demon Soul has been a somewhat source of problems. First forged millenia ago, the Earth Warder, Neltharion, convinced all of the Flights to put their power into it. They had no idea that he would betray them with it, which he did, hence why he is now known as Deathwing
The Demon Soul vanished for many centuries, until it was found by a group of orcs who would soon become known as the Dragonmaw. Why would they become such? Because with the Demon Soul, they could break any dragon to their will, even Alextrasza, the Lifebinder, one of the most powerful dragons in existance. The orcs captured Alextrasza and used her to breed massive dragons for the orcish armies
Eventually, the Demon Soul was destroyed and power returned to the Flights, and Alextrasza roasted orcs