The War Begins

"The darkness was complete. Until a couatl scholar, Hezcalipa, and a blue dragon warrior, Ourelonastrix, rediscovered the prophecy of their progenitors. This gave them insight into the weaknesses of the overlords and their minions, and allowed them to rally the dragons to war"
Draconic Histories: The Age of Demons

Dragons rediscover the Prophecy and rise from their primitive state to oppose their demonic overlords, allying with other draconic species, including the couatls. The common races, still in primitive states, hide from the godlike combatants and find a way to survive.