Ive always been facinated with Araumycos, so i came up with this idea for a mission.
First up i had run a dungeon on the skirts of araumycos before. A sizeable chunk had withered away revealing a dungeon in which the players were sent to with the sponsorship of a Drow house. While scouting out the place they made mental contact with a creature known as "The Shrull". At this point i was not sure what to make the Shrull - keeping it a mystery even from myself.
The large dungeon crawl ended sucessfully and the party disbanded. Its been about a year now and everyone has always been asking me "Who or what was the Shrull?" and i have decided finally to put pen to paper to plot it out.
Anyway to the Idea.
Im a big fan of reading widely and putting things together and adapting them.. so i started out by decideing that "Deeper ruins" beneath the ruins would be well overgrown. I sketched up a map, but i found it to be too "linear". I tried another "too broad" so in the end i decided id save myself the effort and look through my book collection for a map (If one existed!) And i found it in SandStorm - the Burried city of Harrax.
GREAT i thought, just replace Sand with Puffball fungus. too easy. Onto the next bit.
The Shrull had given them a parting gift when they last did the dungeon crawl on the upper levels, leading them to a cape of Lichen, Mosses and mushrooms. I figured a month in game time after departing the dungeon the spores of the cape comune with the players (much like a Myconids spores), giving them familiar headaches and nose bleeds (somthing they got when mentaly communeing with the Shrull), so heading back, the Spores subtly lead them to a hidden passage leading to a shaft decending even furthur into the ruins.
Enter, "Drowned Multum" from the Underdark book. The little entry passage quest there in seemed like a perfect starting few rooms for the crawl... a Moss covered mummy, A black pudding hideing in water, Deadly Magic Traps, Hidden cache of magic weapons and an Ancient armored clay golem. All crammed into 4 chambers.
Better yet it exited out onto a "Drowned" city in its 5th chamber. I figured this could just as easily be a "Burried" city, such as Harrax (Which i decided - since illl never use Multum - to name Burried Multum)
Now i needed some motivation. But for the Record, here's the run down on the level 13 group.
One player was a horned Harbinger, Usually of that long dead Deathgod - forget his name - but i adapted the class for use with her own Diety, Kiarensalee. Another was a Deep Imaskari Ninja/Shadow dancer, which she felt was fitting as The Imaskari use alot of interpretive dance in their current culture. Another, a Deep Imaskari Wizard/Acolyte of the Seven Veils (which i like to call a light-bender). And the final member, Abit of an Oddball, but a continueing character from previous game worlds - a Neanderthal Ex-monk/Barbarian/Frostrager from the frozen north.
The Barbarian doesnt need much convincing to end up in strange places, on strange missions with strange people - hes just a dungeon junky. The Horned harbinger is on a quest to become a Lich. The Shadowdancer was an Agent who suffered alittle "too much amnesia" from her mind wipe upon leaving Imaskar, and the Wizard had self Exiled himself after his own magical dabblings resulted in the death of his loved ones.
So having a think back over everything i read it suddenly hit me - In the Harrax Module from Sandstorm was a Minor Relic known as "the Dead Throne". Whome-so-ever is killed whilst sitting in it is asked by a mysterious entity to lead its undead legions and gain life eternal (as a lich). The trade off, they may never travel 100 feet from the throne or else turn to dust.
As for the Imaskari, i had little idea until i read the module Gduar's Garden... and decided Gduar' would make a good starting point for the Shrull... a Garden of communal fungi acting as a giant stomach tended too by a self evolved Abberation made of ooze who thinks it is a Treant... more work neeed yes. But then i found the 3rd Imaskarcana in its treasure and Lightening struck.
the 3rd Imaskarcana is in the city... but how?
Lightening struck again.
The City was founded by the Imaskari, built up by Mulhorandi Slaves.
but why?
BANG again.
Just by Chance i was reading Fiend Folio (or mm3?) and came across the Kaorti. I had always dabbled with using them - and read that in the Realms, the Kaorti used to be the Quin - a group of mages hailing fom Imaskar. To which end:
The Quin, an Order of Imaskari Mages long ago was experimenting and studying the Far Realm. Perhaps a Weak spot between the two realms existed here - They found it and built a research Lab. Above that, they built a City for their Slaves in the Cavern above. When Imaskar fell to the mass slave uprising it happend here aswell, The Quin fled through the rift they had created and Sealed it behind them - meanwhile releasing all the captured abberations into the tunnels of their Laboratory. The Slaves overwhelmed the city defence force and sealed the Labs off beneath the city to contain the abberations. Then, being underground, were too fearful of the surrounding underdark to exodus so they stayed.
But where does the throne come into this?
A series of mulhorandi kings attempted to rule the city, but their rule was always unstable (Without imaskari magics protecting them the people suffered at the hands of - for my own purposes - the arrival of a powerful lich in the region). The King, Ten Ap, managed to defeat the lich and amidst the loot claimed a simple wooden throne. When Ten Ap was later assasinated in his "newly claimed throne" he rose as a Lich himself and took command of the city by turning those who disobeyed him into the undead. In less than 100 years the living in the city that didnt flee ended up as the undead. Thus the city became a necropolis. And was subsiquently swallowed up by Araumycos.
but what is the Shrull?
My mind turned to the Imaskari Lab beneath the city. Perhaps they had found an entity that absorbs and takes on qualities of what it comes into contact with. When Araumycos forced its way inside the ancient Labs - BANG - between the "tainting" influence of the old sealed imaskari portal to the Far Realms and the misunderstood fungal psychic abomination that is Araumycos. Something strange was born.
an Abberation, that identifys itself as a plant. But it doesnt see itself as an abberation, it sees itself as a "Perfection".
But why is the Imaskarcana still in the city? why wouldnt the Quin just take it into the far realms with them?
a Schism. Some felt, through study, travel to the far realm would be mad. But they were largely opposed by the cocky majority - playing to the overconfident cold logic of the ancient imaskari. When the empire fell, the decenters hid the book. With no time to find it, the Quin mage lord released the Abberations on the decenters - but before leaving, cast "Trap the Soul" on is rival among the decenters. discarding the gem upon the lab floor before leaving.
The Gem was then taken by the few surviving Decenters who fought their way free of the labs where they were captured by the Mulhorandi and probably killed (putting the Gem conveniantly in the Treasury of the soon to be Lich)
- Phew -
Ok... thats just scratching the surface.
Time to throw in some subplots..
an Illithid Ghost, driven mad with hunger for 1 last brain, stalking the halls of the Lab.
some unexpected allies against the Lich in the form of the shamed clergy of a Mulhorandi temple who were unwillingy turned undead and now have been plotting to re-activate the Imaskari Wargolems in their temple basment.
And some non-undead encounters.
A Beholder with a lair on the outskirts of the ruins full of Stone adventurers (surving as a good place to get replacments if people die)
A Lair with some Balhannoths
Etc.
Perhaps some Myconids (If i can be bothered converting them to 3.5), Ooze or More Golems.
Im looking for more inspiration on the themes im going for. If anyone has any other ideas what might be good in an Araumycos dungeon id love to hear them 
I have also long been fascinated with Araumycos. My own suspicion is that it is a "chosen" or perhaps an incarnation/manifestation of Psilofyr, the god of fungus and patron of myconids.
But your idea for it sounds cool also. I bet your players will have a blast.
I changed the plot about the Imaskari Wargolems - and came up with something kinda epic instead.
turns out the frost rager coming there is not random - it was prophecised that "A Son of the Sky Caliph, With Ice in his Veins, Shall draw forth the Light of Aurifar"
So basically i wrote a mission involving the stealtiest member in the party attempting to sneak through the Liches Army and Temple of Loyalist scorpion worshipers to warn the temple of Aurifar the "prophecised" one was going to be trying to reach the temple via the lower Tunnels.. which i also drew up, and given they are the realm of Anubis, i figure its the only place superstitious undead creatures (like mummys) wouldnt actually go. Trouble is its overgrown by Araumycos. But thats exactly why the Temple of Aurifar needs be warned, being all priests of the Sun, they have pendants around their necks that can reflect the smallest amount of light into radiant day light - which seems to have been effective in opening up tunnels through the araumycos (the only reason the Lich doesnt purge the temple at this stage in things).
So while Stealthy mc Stealth Stealth Shadowdancer trys to get to the temple, the other 3 with Tuk-ep-Tuk the mummy priest of Aurifar who conveniantly tells them what the prophecy is head through the catacombs and end up getting hunted by a Purple Worm (which may just eat Tuk-ep-Tuk.. ill decide later).
when he gets to the temple, ofcourse convincing the high paranoid melancholy high priest Sep-nun that its worth the risk to conduct the ritual and incur Ten-Aps wrath as traitors.
The Ritual itself involves, after some batheing in a fetid (once holy) pool and being brought in cerimonial regalia before the Statue of Aurifar in which incantations are spoke to syphon off a life times worth of Sunlight out of the Barbarian into the Statues "Sun-Sphere" in order to Re-ignite it.
Ofcourse they get interupted by the Rival, Evil, Temple of Al-ishtus - as soon as they realise the temple is acting suspicious (tho they shut tight the doors to keep them out, to buy some time) and the rest of the party will be required to hold off the servants of the Scorpion god for just a few minutes.
I considered having Ten-Ap arrive at the apex of the battle. But he cant travel more than 100 feet from his Throne so hes a real Cripple in that regard.
The Cerimony climax's with the Barbarian, now ravaged by a life times worth of heat, sunburn, boils and agony all at once Rageing and Channeling Winter (as he is a frost rager) in order to counter act the unbearable heat of the sun sphere (which is now smouldering to ignition). At the point at which it explodes into fire it takes on the radiance of the sun - and scourges the temple free of the Scorpion worshipers. Even the mummy priests of Aurifar burn, judged unworthy by their diety (but they burn more slowly and deliberately). Sep-nun bids him to reach into the sun-sphere and draw forth the "Flame of Auriphar" then tells him to put down the lich (before crumbling to ash).
Anyway, Epic tragic moment. But i have a problem.
I modeled the Flame of Auriphar, off of the Dawn Star from Magic Item compendium. a +2 Brilliant energy Adamantium Morning Star (now Great-Axe) that Explodes if Sundered or Broken for 200 damage in 10 feet, 150 in 20 and 100 in 30 (DC 17 reflex half).
Problem is, Brilliant Energy doesnt do much against the undead. And the Flame of Auriphar takes the form of the prefered weapon of he who draws it.
I dont want to give them a weapon that is too uber against the undead, so much as a minor relic worthy of the sungod that wont be too imbalanced.
Any suggestions for a good "base" for makeing my Flame of Auriphar? Relic Wise?