Karsus' Folley

 Karsus’ Folly (level 15, every player has to have spellcasting)

You are all proud and famous members of High Netheril who get to enjoy the best parts of Netherese society with none of the dangers of living on the ground. You and your associates enjoy living the high life in the Human magocracy in the city of Eileanar, eternally famous for being created by the young and powerful Karsus. Some of you know Karsus better than others but every denizen of High and Low Netheril have heard of the most intelligent, most ambitious, and youngest archmage ever. At this point every other Netherese city has been fighting the aberrant Phaerimm except your home that’s been well defended by Karsus and his Grand Council. It’s the year 3520 and all of you are part of a classified government project meant to protect the Empire and destroy the Phaerimm once and for all.

Player Equipment

• Any magical armor

• Any magical weapons/staves/wands

• 1 miscellaneous Legendary item

• 1 miscellaneous Very Rare item

• 2 miscellaneous Rare items

Plot

It’s early in the morning and you have all been called to a meeting with Karsus and his Grand Council. A once in a lifetime opportunity to be sure, but if they want to see you you know that your duty must be grand. To fit the circumstance every character should be in their finest clothing and armor and preferably earlier than the stated time.

Everyone is very seriously greeted by the servants not for celebration but for politics and all of the player characters. At the large conference hall every other diplomat and enclave official are either sitting with you in the front row or are seated on the stage next to the Grand Council. After a few minutes of the audience quieting down, Karsus himself, the High Arcanist of Eileanar, appears on stage with a quick and humble round of applause.

Karsus is a surprisingly young human man, able to cast the most powerful spells possible by only 30 years, and his presence commands the crowd easily (he secretly has detect thoughts active to gauge the mentality of his officials). He begins his speech with “Mages of my Enclave, we are all aware of the existential threat the Phaerimm prove to us and what defenses we have adopted to protect our way of life.” He then goes on to describe how the ward around the entire city has been largely successful in protecting them, but it doesn’t work well against the “eldritch occult” that can summon aberrations into the city. The crowd murmurs in agreement but the players may notice some unease with a DC 25 Wisdom (Perception) or Wisdom (Insight) check and recognize some of the members have something to hide.

In the middle of Karsus’ sentence, a golden Deva with a radiant blue halo and eyes, flashes into the middle of the room facing the audience to interrupt and he says, “The course you all follow will lead to your destruction. Change your path now and you can survive. By the will of Mystrl-” Karsus simply twists his hand in the air and banishes the angel back to where he belongs before continuing the speech. This blasphemous act rouses no reaction from the crowd but may upset the more religious player characters (worshipers of Mystrl, the Goddess of Magic, recognize the Deva as one of her servants but everyone knows who she is by name). Karsus finishes off by explaining his future spell with “Once my ritual is done, I will have more than enough power to destroy the Phaerimm once and for all.” This earns a standing ovation from everyone in the building and up on stage.

Suddenly, the doors locked by magic are broken down by the city’s worst enemies, 3 Phaerimm (1 of which casted greater invisibility on itself earlier and starts combat invisible) fly in, ripping apart the nearest mages and servants while the rest teleport away in panic. Soon the players are left alone with the aberrations and Karsus who requests they destroy them and meet him in his office; he then casts time stop and vanishes. The monsters will gladly use their most damaging area of effect spells in an attempt to neutralize the party quickly so they can reach Karsus and assassinate him and thus are especially hostile to anyone who counterspells them.

Once combat ends the party can make their way up staircases and through motion activated teleportation circles to meet Karsus in his observatory, very sternly viewing the sky through his telescope. He solemnly tells them “Congratulations on surviving without weak cowardice. This makes you perfect for a task I have for you.” The party is asked to investigate the Starry Night Apartment Complex where he’s sensed dark powers influencing the citizens there, especially strong in the basement area. He tells everyone to beware since some of the administration has been influenced by the same power (if asked how he knows this, Karsus’ eyes briefly flash with magic, and he says “I have my ways”).

The Starry Night Apartments are located in a bad part of the city and harbors the enclave’s black market but common thieves know not to impede upon the party. Just outside the apartments a shady human man and infamous black market dealer approaches the party to warn them away saying “The folks in this building act… strange at night. You might want to avoid it”. When the party refuses, he shrugs and slinks back to the shadows and leaves the party alone.

Right when the party goes into the shoddy, filthy complex they see a line of residents walking directly into the basement with a mad look in their eyes. Nothing but restraint can stop them from making their way down the stairs and through the long tunnel clearly dug out by every resident of the building over the course of months. The tunnel is 60 feet long and leads to a 30-foot radius cavern that holds a makeshift eldritch laboratory scattered with sigils and scrolls in Deep Speech along with objects made by terrible aberrations. 4 mages recognizable from Karsus’ meeting are here and try to kill the party for seeing too much (15 charmed commoners with daggers become hostile to the party whom the occultists are willing to sacrifice to stop the party).

The writings can be deciphered as showing magical experiments to contact Elder Evils in the Far Realms and harness their power to fuel the magic that protects the city from extraplanar threats. With a DC 20 Intelligence (Arcana) check a player can determine that, with all of the information collected, that success would mean unleashing hordes of incomprehensible horrors upon the Material Plane. They can also hear swirling wind in the next chamber, also behind another tunnel. 

The Warlock isn’t facing the opening when the party enters but he does greet them upon entry. He’s a surprisingly handsome human with a dark brown beard and hair who wears pitch black robes and a dark blue half-cloak (mantle of spell resistance); he’s studying a portal only the size of his head that’s producing all of the wind noises when he says “Ahh. So you’re the ones who have chosen to interfere with my work? I don’t understand why you’d do such a thing? The Netherese Empire is fueled by magical experimentation, this is no different. And this experiment has already begun!” before attacking (2 star spawn manglers that work for the Warlock start combat hidden on the ceiling 20 ft. up).

When the evil mage is reduced to 0 hit points, he points at the portal that has been slowly growing over time and cheers “THE GATEWAY IS OPEN! HUMANITY WILL TAKE OVER THE SPACE BEHIND THE STARS!!” before dying. The portal on the other hand expands so quickly it fills the entire room and envelopes the party before they can even react! They find themselves positioned the same but floating in the starry void of the Astral Sea (effectively space for the characters) yet they can still breath and witness the misshapen, cosmic monstrosities that slowly swim to their planet of Toril. Despite the knowledge of their homeworld about to be attacked by infinitely monstrous creatures, they see a chance of hope in a portal some 25 feet away that appears to lead to a main street on Eileanar.

Once the party passes through the portal they are immediately met with the carnage and destruction wrought upon their home. Various star spawn tears up and annihilate anyone and everyone they come across, Phaerimm fly above buildings to send down deadly spells upon crowds of civilians, and 3 Cosmic Horrors hover on the North, East, and West sides of the enclave to destroy every building in sight.

Every party member receives a telepathic message from Karsus who simply puts “The ritual is ready. Get to my tower! Now!”. The party can see Karsus’ tower from where they are about a mile away on the Southern end of the city but the way there is fraught with danger. The listed encounters are the ones the party can engage in or avoid (but they should probably avoid them to make it to Karsus before the entire city is destroyed):

1. 5 Phaerimm chase the party and target a single character to incapacitate and implant them

2. A Cosmic Horror hovers and teleports overhead, reaching down to smash buildings and pick up people to eat

3. The city is struck with an earthquake (matching effects of the earthquake spells with a DC of 20)

4. A member of the Grand Council is flying away from a hideous and incomprehensible horror and calls out for help from 100 feet away off the road the party is traveling on

Regardless of how many party members survive, Karsus is ready for them to assist in the ritual and his ascension to godhood. Karsus hovers cross-legged in an intricate magic circle, players can make a DC 30 Intelligence (Arcana) to recognize it as an enhanced planar binding spell but at 11th level to harness the power of Mystrl. Every character that can cast a spell can take 1 minute to attune to the circle and in that time, they are forced to listen and witness the terror and death coming from all over the city. However, they can also see small motes of light suddenly appear and strike at the aberrations (a DC 18 Wisdom (Perception) reveals that these are actually Deva of Mystrl here to defend the enclave).

Once everyone’s attuned Karsus can cast Karsus’ Avatar. As the first and only 12th level spell was cast the archwizard’s eyes beam with power and his mortal body breaks and swells with forbidden magic. He screams in the minds of his entire city, “I’M SORRY! WE WERE DOOMED FROM THE START!” and the Goddess he sought to usurp ended her life to cut Karsus off from the Weave. A horde of Phaerimm fly up to try and kill everyone at the very last minute but are repelled by the spell. As a result, all magic dies, the entire world is caught in an antimagic field, and the city falls. The Far Realm entities are banished along with the angels so the work wasn’t for nothing but almost every resident of the Netherese Empire will die in the crashing of their cities. That’s after Karsus’ petrified, boulder shaped form crushes a few buildings on the way down.

The lair beneath the Starry Night Apartment complex

The lecture room of Karsus’ tower