The Dragon Soul was an artifact forged ten thousand years ago to resist the Burning Legion's invasion, created at the suggestion of Neltharion, then the Earth-Warder, using the power of the Dragon Aspects. It was a golden disc forged from the blood of Deathwing the Destroyer, the power of the Old Gods, the souls of Burning Legion demons, and the power of the Dragon Aspects. Its might was extraordinarily great.
Spell-Weaver Malygos had originally intended to use the Focusing Iris directly against Deathwing, who had become the Destroyer. However, during the previous battle against Kil'jaeden the Deceiver, the arcane energy gathered by the Focusing Iris had been almost completely depleted. Unless Deathwing went to the Nexus in Coldarra, the energy stored within the Focusing Iris would have difficulty killing the Destroyer, who was now nearly immortal.
After forcing Guardian Med'an back with a single blow, Deathwing descended directly onto the summit of Wyrmrest Temple. His massive dragon head and iron jaw appeared above the platform.
"Reunion truly brings me joy, Malygos. I am deeply sorry for the Blue Dragonflight's current state." In the original instance, Deathwing should have been speaking to his old flame, Alexstrasza the Red Dragon Queen. But now that Spell-Weaver Malygos, the Blue Dragon King, had not perished, Deathwing chose to provoke the old friend who had once trusted him so completely.
"Using the power of the Dragon Soul to bombard your Blue Dragonflight to death was... a very painful process."
The Blue Dragonflight had nearly been wiped out during the War of the Ancients. It was the lifelong agony of Spell-Weaver Malygos, the Blue Dragon King.
Endless fury instantly filled Spell-Weaver Malygos's eyes. He roared, "Neltharion! Destroyer! Deathwing! I will avenge my people! Because of my trust, they fell at your hands! You, your master behind