The following is my own notes regarding the basic idea of each room in this dungeon and how the occupants of this place interact with one another, their own ecosystem in this fallen place. The players are poised to disrupt its delicate balance, although they risk much themselves beyond the obvious monstrous inhabitants.
Entrance Hall is covered in tapestries, whole sections of which are cut out. An old pit holds dust, dirt, and the dessicated branches of a rose bush. It connects to the west through corridors, through a heavy metal airlock, to the Fungal Pits, to the north to the Foyer, and through a obvious but locked stone passage in the east wall hidden behind fraying tapestry to the Hidden Cave. A hard locked door leads south to the Wrought Iron Maze.
Hallways: Unique traps in various hallways, especially those that loop around. Built as a defense against swarms and useful for training, now turned against the dragon-lich-ooze that will floor through the halls. Crushing walls and ceilings (get the timing right). Electrified panels (insulate or don’t complete the circuit). Spinning blades cover the walls, floor, and ceiling (jump through the middle). Jets of supercooled gel blow forth from carved bestial mouths (Use disposable cover and move fast). Force spike vibrating trap (cover and walk over). Necrotic, weakening fog (divine shields or just move fast).
Fungal Pits: Rat people named Zeromi, Kraxiss, Linda, Marthulmel, Irridissa, and Aea. Want to learn the devil’s true name so they can banish it and take over its old space. Desire a peaceful life, and will offer limited hospitality and commerce unless insulted or attacked. Farm vegetable and meat replacement fungus in pits, and fertilize with stolen spell components. Have a map of the traps. To the north is a corridor connecting to the Summoning Room and the Jail. To the south is a corridor connecting to the Chapel, the Custodial Room, the Training Bunks, and the Training Room.
Foyer is being haunted by hired necromancers unable to escape before dying. Mangled by acid burns, their ghost makes the room appear melted and those that linger too long think they are starting to melt too. Ghostly presence drains those that thinks they have melted, until they actually do. Seeingthrough the illusion, you’ll see two dessicated corpses on the corner with some adventuring gear. Stairs lead down to another dungeon or area.
Jail: Horde of skeletons fighting to escape the cells. Their door appears locked at first glance, though they wait for creatures to approach before revealing the ruse and pouring out. A tough fight, but one that can be made easier using the hallway traps, a practice run for fighting the dragon later on. Some of the skeletons are preserved well enough that their marrow might still be edible. The passage connecting this room to the Summoning Room is easily seen and opened from this side, but is warded and designed to be able to give easy viewing of the Summoning Room, while the door’s movement is hidden from anyone inside the circle. The Jail connects to the storeroom with crudely locked doors held shut with locks not original to the doors.
Storeroom: Supply room is in the process of rotting out and spoiling, as most supplies brought here were when the dragon was trying for lichdom, to supply her servants, apprentices, and hired necromancers. Mostly food and spell components too mixed or corrupted to be worth taking by the rats. Some boxes partially dissassembled for lumber.
Summoning Room: Trapped demon Zyminalixasix, Zym, will make any bargain to get someone to intentionally break the spell circle trapping him, only a deliberate and knowing break by a humanoid will work. Ratlings have rat origins, not human origins, and thus cannot do so (he has tricked them into thinking they need his true name to do so, to manipulate them. He caused the evil rats to break away, “accidentally” suggesting that enough human blood could empower them enough to force him to reveal his name). His true name is Zyminalixasix Ezzerus Oyxanzchtixamil and he cannot break a deal he makes within this circle. His powers include any sort of magic up to and including a Wish spell. He will twist any deal he makes to backfire horribly on the deal maker, even an altruistic release will be regarded suspiciously by Zym as an attempt to recruit him from the Hells although he will merely cause enough harm to dissuade such an altruist rather than attempt to destroy or corrupt them entirely. Assuming it’s deal doesn’t allow it to just kill its rescuer as soon as it leaves the circle. Originally summoned to consult for advice on becoming a lich, when he gave accurate information but made an offhand comment about the dragon not worrying about losing acid powers.
Training Bunk and Custodial Closet: Evil rat people named Ushuk, Shann, Teuaka, and Gorn. Trying to get another to get rid of the devil so they can take its ritual components. Crave manflesh though, and will attack unless intimidated, given a good offer for parley, or beaten back. Have a map of the traps. Living in the old bunk room and using the old custodial room as a storehouse. Drow doesn’t count as manflesh to eat.
Wrought-Iron Maze: Air elemental using fenced area to create a battlefield perfect for hit and run attacks. Deliberately created and uses small pits with fire to create smoke, making itself basically invisible. Is on a training session to practice against mortals for one thousand years, cannot leave the room of its projection effect. Mortals that approach speaking in auran will be challenged to a fight, and can trade mortal fighting techniques for information the elemental has gleaned about the dungeon in its stay.
Chapel: Seven cultists chanting in low tones around a lit brazier. “Warmth to the cold hearts.” “Light to the dark places.” “Ward off the dangers lurking in the dark.” “Nourish the skin of the people.” “Become the shining hope in a world of darkness.” They are too busy with their ritual to talk with the players. Forcing any of their sooty red robes off will reveal them to be dark elves. Even if attacked, they do nothing but continue to chant, resisting nonviolently at any interruptions or disruptions. Do they hold back some ancient evil with their vigil, are they just kooks, or is there a darker purpose? If somehow forced out of their divinely inspired meditative states or mind-read, they are attempting to reach out to a divine god of light or sun and become emissaries to the dark world below, but their ideas of bright sun and light are too dim to draw a god’s attentions, so they toil away. Its closet holds a secret door hidden behind stacked boxes leading to the Storeroom.
Training Room: Training room holds a number of wooden practice weapons, a handful of real weapons, thick woven mats, training dummies, and painted targets. Little value but possible tactical uses in fighting the various monsters or traps throughout the dungeon.
Art Gallery: Bears scenes of sad maidens, queens, and women generally in a romantic style. Lack of maintenance of her ooze has ruined these paintings to minimal value, though with a little work the subject matter can be seen. Klithmnora moves slowly through this area, careful not to tough her paintings.
Cave Foyer: Hosts a collection of smashed and acid etched magical aparati, necromantic in nature targeting a large creature. Successful arcana check reveals these to be for creating a lich, better success reveals that they overcompensated on retaining the acid powers of the dragon, burning out the delicate arcane etchings required to reach lichdom, effectively cutting out the top rungs of the ladder just as the dragon would leap for immortality.
Front Cave: Hosts a small clutch of rust monsters, feeding silently off of bits and pieces of the remains of the dragon’s hoard and piles of equipment. The population went through a boom is has died off, meaning these starving monsters will frenzy at the opportunity to attack metal clad adventurers.
Back Cave: A slumbering dragon skeleton lies atop a pile of bones. Klithmnora the Weeping Knight lies here, signs of acid damage and ooze victims surround her. Any intelligent denizen will know of Klithmnora, at least enough to stay away, and that she only comes out to hunt intruders. Ooze boss is super strong and tough but slow, inexorable mass of dragon bones encased in acidic slime. Slime is resistant to physical damage and takes massive damage from necrotic. Bone mass inside is resistant to magic, heals from necrotic, and weak to bludgeoning. Ooze mass lost first, then bones, then finally just an animate dragon skull demi-lich. Perfect solution, making the battle easy is to get the ooze to chase you through the traps to hit it with the magic ones first, except the acid, to burn off its ooze while still attacking it. Then, get it into the acid to soften its bones and follow up by hitting it with the physical attacks to reduce bone mass. Finally, lead it to a room that offers good tactical advantage and kill it. In big spaces it can lash out with multiple pseudopods and attacks, saving its limited demi-lich magic for real threats, but in corridors and tight spaces it can move only as fast as a normal human, with the occasional boost when it aligns itself right, while making a small number of weaker attacks. While her attempt at immortality has failed, those hit by her bone attacks will be infected with her spirit, a new affliction corrupting their bones into a facsimile of dragon bones. The boon of power may become a degenerative disease ruining a humanoid body or perhaps as they push through its ravages, Klithmnora’s wayward spirit will find a strong body with which to anchor herself to the mortal world once again.
Hidden Cave: Hides the remaining pieces of the dragon’s wealth not squandered, stolen, or eaten, it is reached by the dragon through a pit of bones, although the barely sentient lich-ooze no longer remembers such a thing. The secret entrance is for supplicants to approach, and is opened from one side by the presence of presented valuables in the manner of an airlock and opens the other way by the lack of detectable valuables. Her hoard is mostly a collection of rare bones, although some gems, coins, and magic items survived her desperate spending in the course of pursuing lichdom.