CP2053 - Shadowrun / Cyberpunk
Dragons existed for decades before the awakening, but in dormant form. The dormant form of a dragon is a nuclear or thermonuclear weapon. During the early years of the Awakening, a great many nuclear missiles were launched, some nuclear bombs dropped. But some missiles left their silos and instead of exploding on arrival, turned into gigantic, nuclear fire breathing monsters.
For months the skies were unflyable due to the packs of small to medium to large to gigantic sized dragons that would pluck passenger and cargo jets out of the sky or simply roast them on the spot. This cut into the bottom line of the megacorporations, not to mention culled some of their executives right out of their private jets. It would not do.
Plagues engineered by megacorporate scientists proved very effective in eliminating the dragons. They also proved very effective in eliminating 10% of the world’s population, and mutating another 25% or more into various species of metahuman.
Of course, there are rumors that some dragons were still in their dormant form, hidden away in missile silos or nuclear submarines. The lifespan of the plagues is unknown, but if the plagues have passed, there may come a day when the remaining dragons awake and ask pointed questions like “where have my people gone?” right before they burn the corporate fortress towns to carbon.