Hidden around the middle of the post is the idea that "Dragons are more real than other things around them. They are the Most Real Things." They shape reality around them. Their preconceptions warp the environment. Reality yields to comfort them.
"A terrifying concept." A friend told me. I agree, and for that I love it.
I ended up making a (bad) map for The Dragon Hole and ran it a few times for three different groups. It was quite a hit. Volectra was a crowd favorite. It occurred to me while running it for my Tidelock campaign, though, that I would need to think about what would happen after The Dragon Hole. After the precarious stalemate of power was disrupted in the dungeon and its factions inevitably battle it out over control of Mother's hoard, what then? The following questions needed answering:
If particular dragons were alive after the incursion, if any, what course of action would they take? What could they become?
How do these dragons interface with the world (and reality) at large?
What happens when we crank their environment-warping abilities to 11, to the societal scale?
For each dragon, and each combination of dragons this will likely be different. How the party has affected the Dragon Hole should change this as well. To keep it simple I will consider individual dragons, although pairs (like Volectra and Vulpernia, or Scabbermouth and anybody) can certainly exist.
Garnos the Bestial -> Garnos the Dungeon Underlord
The Dragon Hole then develops a new pipelined ecology, a sort of food chain hierarchy all flowing down to Garnos and his treasure pit. Hirelings, adventurers, local wildlife all feed into the ecosystem. Things come and are eaten by things which are eaten by bigger things which are eaten by Garnos.
He'll get fat and lazy, a big ol' beer belly. He'll sleep for months on end, waking up only to relish the opportunity to eat the occasional hoard-thief.
In short, Smaug.
Quest Potential: Garnos doesn't interact with the outside world, and he hoards his treasure jealously, so that massive motherload is still there. Treasure lures the entrepreneurial type. Lazy fat dragons with massive hoards lure other less-lazy, less-fat dragons. It's only a matter of time until the Dragon War starts and Garnos finds himself besieged from all sides.
Volectra the Painted -> The Sapphire Queen
Over time she'll rest on it. The sapphire will crush and seep into her scales. She will become The Sapphire Dragon, the Queen of the Painted Palace ("Dragon Hole was such a vulgar name!"), The Sapphire Queen.
To her delight, the Elves will learn of her adoration of them and flock like bees to pollen. The Elf King will marry Volectra, and she will rule over them as a fair and firm queen. They will teach her their magic, and soon enough she will take on a beautiful elven form, graceful and sparkling like the ocean at sunset. She will heed the whispers of her ancient advisers and love the stoic scions that guard her palace. She will be a good queen.
At Volectra's command the elves will toss out all of the gold and silver ("too gaudy, those metals!") from Mother's hoard. They'll practically give it away by the truckload to neighboring provinces. She will keep the gems and purge the place of tacky metals until every ounce of it is gone.
Peasants will stuff their mouths full of gold false teeth, merchants will use silver for paperweights, the value of gold and silver will plummet so drastically that it'll crash all adjacent economies. For adventurers, the value (and XP given) for gold and silver objects brought back to civilization will decline.
At first, silver and gold brings back only 90% of the value/XP. After the next venture only 80%. Then 70%, and so on. On and on until gold and silver is worth practically nothing, and peasants use ancient golden coins, that used to feed a family for a year, to skip along river tops like stones, for fun.
Quest Potential: Baron Garfield, who owns the biggest (and only) gold mine in the region, wants you to put a stop to all of this gold and silver coming from "The Painted Palace" (he'll say, with disgust). Put a stop to it by any means necessary. He's willing to pay you in sea shells/bottle caps/whatever post-apocalyptic currency now exists.
Vulpernia the Shepherdess -> Vulpernia the Terrible
Vulpernia will abandon or eat her adorable critters, opting instead for re-purposing her drakencult to specialize in kidnappings and extortion, attempting to abduct every attractive young adult man within a couple hundred miles. She will hoard hot young men like they're hotcakes. (Which is what she'll call them. Hotcakes.)
Slowly she'll develop a considerable collection of hot guys. She doesn't actually know what to do with them, so they just kinda lounge around all day, looking pretty. Maybe she makes bands out of them. A massive harem of male models, singers, artists, bad boys. She'll outlive them all. Eventually she'll need to get rid of some to make room for others.
Vulpernia will eat the rejects (abductees who don't pass the Hotness Test), scorn those she's gotten bored with, and exile those that have aged or been mutilated out of their hotness to Scabbermouth's (old or current) lair.
Quest Potential: An important Hot Boy has been abducted! A prince engaged to wed in a powerful union, perhaps, or maybe one of the PCs. A king's ransom has been promised for his return.
Ashrendar the Architect -> Ashrendar the Orientalist
Ashrendar will pursue scholarly studies, secure in his position as Lord of the Dragon Cistern. He'll study history, anthropology, economics, cultural studies, architecture. He will become obsessed with one particular culture. A land and people far away, distant yet peripherally accessible.
He begins forming an exoticised intellectual construct of this culture, along with his scholars. To anyone who's actually lived in this culture, or done any good-faith research, it will be preposterous.
Slowly, this intellectual construct, which is divorced from truth, starts to become reality. Ashrendar's confidence in it makes it reality. It is the confidence of dragon-hoard-tenured academics, a confidence built upon decades of inbred scholarly work reinforcing itself. A confidence with evidence but not truth. It is a Juggernaut of Reason built upon a foundation of false assumptions, piloted by an super-real Gatekeeper of Knowledge drowning in a Sunken Cost Fallacy.
As it gains traction, the culture starts to mirror Ashrendar and his minions' artificial construct of it. People in the culture begin acting more savage, more degenerate, more cruel. They become as Straw Men, simple and infinitely understandable (but only through Ashrendar and his academics). Only through His filters can They be understood. The culture will be ultimately Other-ed out of their Humanity. Perhaps this is where gnolls or orcs or some other unfortunate race comes from.
It's a horrible way for a culture to go - to be poisoned by a creature halfway around the world, who won and erased the war before it ever began, before anybody even knew about it.
Some powerful individuals will be immune to this effect. Sovereigns, demi-gods, those protected by the cancelling anti-preconceptions of other societal-entrenched dragons. Perhaps adventurers, too. To all else these poor souls will seem to slip into madness and dementia as the history and culture of their nation are retroactively rewritten before their very eyes. Events will be remembered differently. Books will rewrite themselves in the night. They slowly become estranged to their own culture. They will be remembered as Mad Monarchs and raving lunatics.
Quest Potential: A Mad King/Queen from a barbarous kingdom pleads with the PCs to assist him/her in disproving the scholarly works of Ashrendar and his librarians, equipped with witnessed half-truths and fabrications. If Ashrendar and his subordinates cannot be convinced then revenge is the only recourse. They are prepared to die for this cause.
Scabbermouth the Phlegmatic -> Scar the All-Breaker
His ability to break will become fine-tuned. Eventually, with a gaze, he will shatter the limbs and psyches of even the powerful. He will drag himself out of the pool and prosper in his suffering.
He will gather followers: amputees, lunatics, social outcasts. An Army of the Broken to march on the Unbroken world. The world is wide and powerful, but the Army has a zealous dragon at its helm, and that counts for far more than able bodies.
He will take on a new name: Scar the All-Breaker, and he won't stop until every single creature on the face of the earth is broken, just like him. He won't stop until healthy babies are mutilated out of the womb and holy men spend their days punching holes in the wings of flies. Until the Laws of the Broken are followed by All.
Quest Potential: Revenge. The Army of the Broken mutilates the party, or someone they care about. Or someone important. Perhaps an entire city. The Army and its laws forbid healers, making adventuring a dangerous profession. Being Broken it becomes easy to infiltrate the lair and trace everything back to Scabbermouth.
Or, perhaps, join the Army of the Broken. There's a certain equality to it, after all. And adventuring types tend to be good at breaking things. Scar rewards those loyal to him very well.
The Emerald Egg -> The Dracolich's Daughter
Eventually, she will finish the Dracolich. She believes this to be Mother. It is not. It is something Else. Something not of this world. It will whisper to her ear, in Mother's voice:
"Daughter, my dearest love. My Favorite, you have done so well. I am almost ready to return, and we shall be together forever, again. All we need is more meat and more time."
She'll send out ghouls, polymorphed and illusioned to look like normal people, on infiltration missions to bring back hostages and bodies. Only human bodies will do. Paranoia and chaos will spread. Societies will crumble. People will become hunted like foxes as Terminator-like undead roam the countryside at night, ni-invincible horrors collecting man-flesh, howling eldritch cries.
When Emerald gets enough meat, a small country's worth of flesh, then the Dracolich will be truly ready. It is a cruel god with all the reality-tearing powers of a dragon and without any of the humanity. The world may not survive its coming.
Quest Potential: Evil roams the countryside. Refugees pour across the land, speaking of friends and family taken by inhumanely strong doppelgangers of loved ones. It isn't safe to travel at night anymore. It's only a matter of time until they arrive. The players are confronted by a ghoul polymorphed to look like one of their own. It will attack with terrible strength and savagery.
When it reverts to its true form, they will know what it is. They'll have seen them before, in The Dragon Hole long ago...