The Return of the Hearth King of the Dragons

There's something called the return, which is basically how people rediscover and figure out a way to get magic back into the world. And when virtue begins to be restored to creatures, the dragons vow that they will never again abandon the knowing. The metallics and the chromatics by avan quintus have both disappeared off the face of the world,. So whether they kept their promises kind of up to your interpretation.