"We never paid any heed to the ancient prophecies... like fools we clung to the old hatreds... and fought as we had for generations. Until the day the sky rained fire, and a new enemy came upon us. We stand now, upon the brink of destruction, for the reign of chaos has come at last."
Warcraft III: Reign of Chaos
"We never paid any heed to the ancient prophecies.."
Wrathion as Medivh in the past, foreshadows a terrible threat to Azeroth is coming.
(Wrathion shows us a "vision" of a ball of green fire hit Azeroth)
"like fools we clung to the old hatreds..."
Alliance - Horde War in Mists of Pandaria (Warcraft: Orcs & Humans)
"and fought as we had for generations." until now!
Escalation to Siege of Orgrimmar (Warcraft II) (The Second War - civil wars among the Orcs)
"Until the day the sky rained fire, and a new enemy came upon us."
Wrathion's vision. The Burning Legion, the coming storm. (Warcraft III)
"We stand now, upon the brink of destruction, for the reign of chaos has come at last."
World of Warcraft: The Dark Below (Dark Below.. the storm!)
- In my opinion, it's all there within the cinematic of Warcraft III: Reign of Chaos