Help designing Spires Against the Stars

[Braininthejar2]

Hello. I'm planning a high level adventure, and I could use some feedback designing the temple-fortress the party will need to assault.

The Party: level 20, and oversized with NPC allies - The team leader is a druid specialized in summoning. A bit of everything.

The Enemy: One of the end bosses of the campaign, an epic ranger has been using astral travel to repeatedly hound the party. For all her power though, she doesn't yet have the resources to have an inaccessible pocket plane hideout - instead she has allied with the church of Beshaba - the church has a serious bone to pick with the players, so they will let the ranger use their most secure temple as a haven to cast astral travel from. And if the PCs show up on their doorstep, they will gladly sacrifice some minions to delay them until the ranger's party wakes up and faces the PCs alongside their high priestess.

The Location: The longest description of Beshaba's center of worship (and indeed what gave me the idea - it just happens to stand smack in the middle of my campaign area, which I discovered by accident) is this:


The most holy center of Beshaban worship is the Spires Against the Stars, a hilltop fortress north of Saradush in eastern Tethyr that was once a vampire-haunted, abandoned castle of a noble family. The Spires is headed by Nails of the Lady Dlatha Faenar, an elderly but (through magic) still lushly beautiful priestess who has ruthlessly slain her rivals and so far eluded all attempts to destroy or depose her over the course of almost a century. Dlatha is said to be able to wield magics too potent for most mortals to use or comprehend.

So we have an old vampire castle converted into a cathedral (?)

Also a high priestess, and some Black Fingers assassins. Undead and demons are to be expected (bebiliths and bodaks are Beshaba's associated monsters) What else should I use?

Expected Player Plans: having seen the party overcome previous obstacles, I am expecting either of those plans to show up:

1 Frontal assault - summon a dozen elementals (air to attack from the top, or earth to earthglide). Ram an elemental monolith through the gatehouse. Drop a frostfell in the courtyard once the defenders show up.

2 underground scouting - use earthglide (earth elemental wild shape) greater blindsight and mind blank to move in undetected and scout the place, then find the way to do the most structural damage prior to the main assault.

3 collapse - repeatedly earthquake the place, send elementals earthgliding through rubble to engage the survivors.

4 conflagration - spam summon nature's ally - send a dozen thoqquas burning lava tunells through stone walls. Attack any enemies that try to escape the fire.

5 bypass - shapechange into a beholder, make own entrance through the foundations, past most defense lines. Use antimagic cone to neutralise enemy casters in confined spaces until the barbarian can whack them.

6 greater bypass - burn some resources to wish the party past the defenses (use the 'transport' option of the spell, but specify 'not teleport' - the party will be shrunk inside a fine flying ball that sneaks past the guards and around warded areas, going under doors and through keyholes), drop inside the inner sanctum in hope of whacking the boss before she's ready, and then fight their way out.





So, what else could the fortress contain, and how would a cunning and powerful high priestess protect her home from high level intruders? I love building dungeons, but most typical defenses would be laughable against this level of power.

[Braininthejar2]

Hmm... I've realised that I have some old Warhammer modules I never DMed. Perhaps I could use castle Drahenfels as the base for the layout. (and putting some rooms in paralell planes would certainly thwart attempts to go through walls...)

[Gildedragon]

Spires points to it being a many-towered fortress.

Have lots of narrow bridges joining the different towers and baileys

[Braininthejar2]

The campaign has already had a drow city, and wood elf city battles. That might be enough bridges. :smallcool:

Than again, that's a good place for a bebilith to wait in ambush

[Gildedragon]

The campaign has already had a drow city, and wood elf city battles. That might be enough bridges. :smallcool:

Than again, that's a good place for a bebilith to wait in ambush
Some of the bridges may be broken. Flight is necessary.

Also these would be, overall, fairly wide bridges, more meant as chokepoints than anything.

Some might be rickety boards though.

Also mix in a lot of ramps and stairs.

[Braininthejar2]

Remember that the castle used to be abandoned and haunted. Now it's a major religious site - to an evil faith that wouldn't mind a pilgrim meeting an unfortunate end to falling masonry, but still. I guess it's in much better repair.

I'm still trying to imagine how it looks like as a temple - the religious ceremonies of Beshaba seem to involve drinking, undead, and wishing ill to people.

So perhaps the temple is a converted dining hall?

With enough magic, a building can be heavily modified, but how much would be worthwile? What does the temple's status involve? I guess they do get some pilgrims, but probably not many - it would be clerics wishing to bask in their goddess' power, or people who hate someone enough to willingly accept misfortune upon themselves just to make sure they harm him more.

[Braininthejar2]

Okay... so, my vision is starting to coalesce. The fortress would look more or less like this:

1 Main Layout: A castle on a rocky hill, with four tall towers in the walls, some buildings inside the courtyard (a smithy, a stable, servants' quarters repurposed as a guest house for the pilgrims) and the main building, which takes one corner of the castle (the windows face outside over a cliffside, giving a good view of the surrounding valley from the throne room). The castle's tallest tower rises from the main building, giving the whole castle an appearance of a clawed hand (the five towers forming four fingers and a thumb.)

2 First line of defence: Undead, including some bodak knights. The High priestess will take part in the battle, but will use contingencies and sacrifice some allies to escape if things go south.

The fortress has some runestones embedded in the walls, binding it against any magic that could be used to collapse the walls.

A curious thing about the main tower - it can't be interacted with. true sight indicates that it is real, but trying to attack it causes intruders to pass right through it - it has been shifted between dimensions, and is not entirely there. (in fact it goes through the building, occupying the same space as some other rooms.)

* Now, do I just handwave the thing with "an epic spell from the high priestess" or is there a more rule-neat way to make this work? *

3 Main building: The mansion contains some infrastructure, like the main kitchens, and the staff's living quarters. It has some traps that can be dangerous to those not knowing the layout - normally they are a form of sacrifice to Beshaba, randomly hurting guests, but on full alert they are upgraded to be deadly. During the retreat the priestes will wake up the boss, setting up a battle in the great hall.

4 The catacombs: if the party wins, the villains will retreat - they have more tricks up their sleeves still. The path leads down to the catacombs, filled with spare undead, necromantic experiments, and hidden ritual rooms. Also the treasury if the party figures out how to get in.

5 The tower: deep within the catacombs there is a portal allowing entry to the bottom of the central tower. The building is bigger on the inside, and filled with planar anomalies, private hells of those who displeased the high priestess, and deadly environments to trap and kill the most dangerous of intruders. If the party gets through those, the villains will make their last stand in the chamber atop the spire.

How does that sound?

[Braininthejar2]

Perhaps I should have named the thread differently...

[John Longarrow]

For primary defenses...
1) Protection from Good and Protection from Evil cover the entire place, especially the lower levels. Should keep summoned creatures out.
2) Each spire has an immovable rod at its tip. They are built to be supported by the rod, but their bottom levels rest inside the hill. No worry about removing the hill beneath.
3) Spires are linked by enclosed bridges. No need to let outsiders see what's going on inside...
4) First line of defense in the hill are incorporeal undead in a set of catacombs underneath the towers and outside the protection spells.
5) Most of the towers are covered by dimensional anchors. Also entrances are covered by walls of dispelling.
6) Lots of resetting summons traps around the outside. Anyone hanging around is bound to get something nasty showing up.
7) Very active defenses. Outsiders who came through gate spells provide a fast scouting force that, once it identifies an enemy teleports back to a rally point to call in reinforcements. Anyone staying outside too long (or busy fighting summoned creatures) gets dog piled by nasties.

Main items to look at are "How do they stop someone from knocking over the towers" and "How do we stop an enemy from just popping in" when setting up defenses. The owners HAS been around a long time so has probably had to deal with lots of nasty tricks.

For one very nasty set of defenders, undead with lifesense and casters with mindsight. Both work great at overcoming mundane stealth and work against many magical forms to. For extra evil, have a necropolitan beguiler who's dipped mind bender and has both!

[Braininthejar2]

A druid earthgliding in earth elemental form with mindblank will be unseen, and protected from mindsense, I think.

Will she be felt with life sense?

[Fizban]

The fortress has some runestones embedded in the walls, binding it against any magic that could be used to collapse the walls.

A curious thing about the main tower - it can't be interacted with. true sight indicates that it is real, but trying to attack it causes intruders to pass right through it - it has been shifted between dimensions, and is not entirely there. (in fact it goes through the building, occupying the same space as some other rooms.)

* Now, do I just handwave the thing with "an epic spell from the high priestess" or is there a more rule-neat way to make this work? *
Wibbly plot effects can be justified via plot fiat, Wondrous Architecture (basically magic item) fiat, or epic spell fiat. In particular, you could simply say that the area is covered by a Mythal (Player's Guide to Faerun) epic spell from the previous (or current depending on how high level the priestess is) owners that simply negates problematic spells like Disintegrate and Earthquake, makes the tower wibbly, whatever. Mythals are basically the missing piece that takes epic spells from "theoretically able to fiat anything" to actually doing it. If you're using epic NPCs already and want there to still be hard counters to high level magic, mythals are basically the character based rule that lets you do it.

Failing that, magically enhanced walls get saving throws, but you could also make a wondrous architecture based on Greater Spell Immunity that simply makes them immune to the offending 8th level or lower spells.

More specifically:

To stop earthglide scouting and thoqquas, simply have metal outside/inside/lining all the walls. If you allow attacking while earthgliding they can still bash their way in, but it won't be quiet. This should be standard on any serious fortification.

If they word their transport wish to move them physically rather than the usual flat bypassing of all planar wards and defenses, that flying ball still passes through everything on the way. Dispelling fields or AMF effects will wreck it just fine.

The fortress should obviously have Forbiddance running, and you can cheese it to taste by shaping holes in the area so that they eat damage for moving around. Shapeable areas can go as low as 10' dimensions. And then fill the holes with a second overlapping Forbiddance effect so that there aren't actually any gaps and they take damage every 5' instead. Or an arbitrary number so they just die immediately.

There's basically nothing to stop the raw power of Shapechange aside from general anti-magic, but a beholder's antimagic cone doesn't protect them and they have little in the way of defenses themselves.

[ATHATH]

Maybe throw some Cursts in there as well?

I'm sure that you could have some fun with the Conductivity feat.

The Eyes to the Sky and Live My Nightmare feats might help to dissuade scry-and-die tactics.

[John Longarrow]

A druid earthgliding in earth elemental form with mindblank will be unseen, and protected from mindsense, I think.

Will she be felt with life sense?

Fizbin covers some of the best ways to protect yourself as a high level caster.

For life sense, the creature with it sees the light that living creatures emit. As such they would see light sources moving around even if they are mind blanked and invisible. This is why you want a big open spot underneath the towers that allows incorporeal undead to hang out in the dark, waiting to see someone trying to move by.

[Braininthejar2]

Maybe throw some Cursts in there as well?

I'm sure that you could have some fun with the Conductivity feat.

The Eyes to the Sky and Live My Nightmare feats might help to dissuade scry-and-die tactics.

I was thinking of some curst guards that keep coming back... and some curst comic relief, like a butler who displeased the high priestes, and got cursted, so the rest of the staff can keep 'killing' him on a whim.

[Florian]

It´s astonishing that you let your group get away with abusing such cheap methods.

Ok, some thoughts:

The old castle is just that, a plain old gothic-style castle and that´s it. It more or less has no use and is a decoy and resource trap.

The actual "Spires" are five free floating, invisible towers that slowly circle around the central keep below in a pentagram formation.

I like the idea of using Curst and other rejuvenating undead, so I´d staff the lower castle with those that fell out of Beshabas favor and the upper castle with the ones in her good graces.
The idea of using a small Mythal that gives the basic protection that should be fitting to a high temple is a good one and fitting for FR.

[Braininthejar2]

Cheap? don't tell me. That druid once dug through a river bank to flood a mine I wanted her to explore.

Then again, her enemy is using astral travel to attack her repeatedly without personal risk - so she's getting what she's giving :P

[Braininthejar2]

Started making the map - considering the scale so far.

Would a 60 by 60 meters square with the 30 by 30 meters main building, and the walls 20 feet high be okay?

It's a very important castle, but not a particularly big one.

[Florian]

That is... very small.

I´m living in a rather modest terraced house/townhouse and that is 5mX15m with a garden of the same size.

Maybe you should google some actual castles/defensible monasteries? "Castles of the Loire" should be a good start.

[Braininthejar2]

Hmm. I used the inner fort of Malbork for reference - which is a small part of a huge castle.

http://www.nid.pl/imgResize.php?img=L3VwbG9hZC9pYmxvY2svNWNhLzVjYTlk NjVhOWY4MjU1ZDczOGE5ZTEwNDNiZjgwMjczLmpwZw==&scale=3

[JustIgnoreMe]

Hmm... I've realised that I have some old Warhammer modules I never DMed. Perhaps I could use castle Drahenfels as the base for the layout. (and putting some rooms in paralell planes would certainly thwart attempts to go through walls...)

Castle Drachenfels is a fun module, I ran it for my Pendragon players. It is very much a gritty Warhammer-type scenario, but adapting it to other games is perfectly possible.

I always though that the "twist" (i.e. the secret win-button) was hidden away too well (as in there's no actual way to find it), but that's reasonably realistic: why would you advertise such a vulnerability? Although, with D&D access to Commune and other scrying, it's possible that the party would be able to find it too easily.

[Braininthejar2]

Okay, making the first attempt:

(The map will change as I update - so will the descriptions. Right now, the castle really does look small - I've been trying to keep it "dense" to get the towers closer together for a more 'vertical' look, as befits the name)

http://i1036.photobucket.com/albums/a441/Braininthejar2/Castle%20plan%201_zpsfm21ppkh.jpg?t=1495372263

1 - gate house. (Still thinking about the defenses)
2 - archers tower - this tower overlooks the road to the castle.
3 - tower - this is the second most obvious slope to attack. This tower protrudes out of the wall, better to fire at intruders scaling the walls
4 - prison tower - used to be the castle's main dungeon. Now the prisoners are rare, and "used up" very quickly, so the tower mostly houses undead.
5 - The main tower. It seems to be a part of the main building, but is actually shifted between dimensions - it is only accessible from the underground levels.
6 - stench tower. This tower was used as an outhouse, and to dispose of trash, dumping them down the hillside. The current owners have come up with a slightly less stinky option, dropping it all in the basement for an othyug to eat. (the priestess took an opportunity to experiment on it - a template makes it negative energy aligned, preventing the undead haunting the castle from bothering it.)
7 - the main building. The walls facing the courtyard have galleries. The opposite side has large windows facing out over the cliff. The small corner towers contain stairs, allowing roof access from the castle walls.
8 - main entrance
9 - the well.
10 - the servants house - housing much of the castle staff. It also has guest rooms for the pilgrims visiting the spires.
11 - the carriage house
12 - the stables
13 - the barracks - housing most ordinary guards of the castle.
14 - the smithy. This building has been recently expanded to also house several nightmares - they couldn't be kept in the stables due to fire hazard.

[Braininthejar2]

Okay, while I'm thinking of the technical stuff, I'm looking for some flavour ideas.

This is a dark, gloomy castle with scheming priestesses, some demons, and undead.

It is dedicated to Beshaba.

How is it different from a similar castle dedicated to... let's say, Shar?

[Braininthejar2]

So... despite what Florian said, a 30 by 30 meters building is big enough.

I have multiple guest rooms 15 by 20 feet with room to spare.

I could actually use some more ideas for rooms to fill in some gaps:

* servants' rooms
* guest rooms
* the priests' chambers
* master's bedroom
* kitchen
* pantry
* wine cellar
* common room
* servants' common room
* armory
* library
* treasury
* bathroom
* toilet
* dining/throne room
* trophy room

What else should there be there?

[Braininthejar2]

Okay. I'm working on several locations at once, but it seems I've forced the party to go here first, so I will focus on this one now.

Adding some details to the map in the previous post.

changes: - the main building has a chapel extending from it on the ground floor. Will add it next time I redraw the map.

Defenses:

With the castle being Beshaba's great sanctuary, the high priestess gains enough donations through her influence in the church to pay for defenses that need to be refreshed. As such, the whole castle is unhallowed ground, with a death ward effect that targets believers only. (the steeds in the fortress are branded in a ritual that marks them as property of the church, allowing them to also benefit from this protection.) The courtyard of the castle looks unnaturally gloomy regardless of the weather - a side effect of shifting a part of the fortress to the Plane of Shadow - allowing light-sensitive undead to function there without penalties.

Each tower has a rune-carved basalt column inside it on the ground floor - forming the core of the spiral staircase. These maintain the magical protections of the sanctuary - making the walls more resistant to damage, and protecting them from magic that could reshape them - earthquake, disintegrate, and stone shape effects are ineffective against them.

The archers tower has a pair of ballistas on the third floor - due to the construction of the windows, each can only be aimed in a very limited number of directions, but it's enough for one to shoot down the approach , while the other covers the bridge in front of the gate. There are two more ballistas on the roof of the main building.

In general the castle is very ominous, and covered in gargoyles - these seem to move when you're not looking (they aren't monsters - it's just a small illusion to confuse intruders. But the magic mirror in the gatehouse allows the priest on guard to look through the sculptures eyes, keeping an eye on the area outside the walls.)

The gatehouse has a narrow bridge approach, a portcullis, a ceiling hole to pour molten tar at intruders, and a second portcullis composed of two spiked pendulums that come crashing down, meeting in the middle, possibly crushing an unlucky attacker. Apart from mundane defenses, there are obviously magical ones too. There is a wall of greater dispel magic in the entry, and a symbol of death over the gate on the inside of the fortress, activating when somebody walks through. If they're believers, they should already benefit from the death ward effect... It won't stop a high level intrusion, that will likely fly over the walls, but at least it won't allow infidels to just walk in through the front door.

The tops of the towers serve as magical lightning rods, protecting the castle from bad weather, and storing some of the energy in the process - a corporal creature larger than a small bird flying two meters or higher over the edge of the walls will be struck with a lightning arcing from the nearest tower, dealing some damage, and alerting the defenders of intrusion.

Castle staff and guards:

servants - civilians who, through various circumstances ended up serving in the sanctuary. In case of an attack, they will try to get out of the way, and failing that - die in a crossfire.

soldiers - about twenty men scattered around the castle. They are elite (level 4), but in a real attack they would still be fodder, and they know it. They try not to be too unhappy about it, because losing faith might cause their wards to fail. In case of an attack, they mostly shoot with crossbows and ballistas, trying to leave close combat to the castle's supernatural defenders.

wraiths: Ten men who signed contracts to leave their souls to the church after death, in return for suffering no misfortune in life. The foolish act bound them to the fortress as guards: their bodies are buried in chains in the crypts beneath the castle, while they roam the fortress in torment - during the night they also venture outside the walls. They will stay hidden most of the time, but will gleefully swarm any living creature that isn't warded against their touch. Some of them have gained a couple HD since they got here, allowing them to gain lifesight.

nightmares: there are three nightmares stationed in the stone stable next to the smithy. They will raise an alarm if they detect an intruder, but won't engage on their own, preferring to wait for their riders to show up. They know about the lightning ward over the walls and will use etheralness if needed.

undead: 20 dread warriors, usually stored in the old prison tower, can be used to double the castle's regular defenders in case of emergency.

othyug: kept in the cellar underneath the tower of stench, and used for trash and sewage disposal. Won't actively fight unless someone actually drops down - it's template gives it enough negative energy vibes for the wraiths to leave it in peace, and it is content to be regularly fed.

priest: a mid-ranked cleric in charge of the gatehouse. Mostly sits in front of a magic mirror, running surveillance. (there are several clerics in the castle, but most of them spend their time in the main building - only one at a time will get a guard duty)

curst: Edward the sad is a curst warblade in the service of the church. He mostly resides in the prison tower with other undead. If there is trouble, he will lead the dread warriors into the courtyard, trying to contain the intruders until the high priestess is ready for a counter attack. If the enemies are airborne, he will call his nightmare steed to reach them.

banshee: Lady in White spends most of the time on the top of the prison tower. She won't join the fight unless Edward already has, or someone intrudes upon the tower directly. She will open with her keening, trusting the castle wards to prevent friendly fire.

mage: Galdor is the castle astrologer and alchemist. He spends most of his time in his tower. If there is trouble, he will look down to see if he can end it with a well placed stinking cloud. If the trouble is serious, he will not join the fight in the courtyard, instead trying to get to the main building to join the high priestess' retinue.

the captain: Jillian is a darkly sardonic woman in her fourties, a captain of the guard in charge of the human guards. In reality, she's Jinx, a beshabite corruptor of fate yugoloth, and a high level assassin. Will engage intruders alongside the guard, but if faced with powerful enemies, will retreat, leaving the stalling game to Edward and Lady in White.

The elemental: Sound-of-coffin lid-caving-in is a corrupt earth elemental. He's six meters tall, and looks like a mass grave turned inside out. He can barf forth some skeletons in more fodder is needed, but his main job is earthgliding through the earth around the underground levels, keeping watch for tunneling or earthgliding intruders. In case of a direct attack, he will wait for melee to start, and then burst through the cobblestones of the courtyard, directing his attacks on any squishy targets who aren't flying.

High priestess and her retinue: work in progress.

[Braininthejar2]

Main building (map to be made later)

Ground floor:
- main hall: a pit trap that would sometimes be activated to randomly give someone a painful fall - but on full alert gets upgraded to lethal with a pull of a switch.
- cloak room
- guard room
- kitchens, with a pantry, wine cellar, and a small lift for sending food to the second floor.
- the big bathroom
- storage areas and servants' rooms
- tithe room - a small treasury for items the pilgrims have brought as sacrifices
- chapel entry: the chapel has a statue of Beshaba that will curse you with bad luck if you don't follow the correct protocol while approaching the altar, as well as an entry to the crypts.
- priest's room: used to belong to the castle cleric, now it is used by the priest in charge of the chapel.
- temple archive/scribe room

First floor:
- guest rooms
- living room
- trophy room- used to contain hunting trophies. Now it displays trophies from the Black Fingers' most infamous strikes against infidels
- library
- meditation room

second floor:
- the master's chambers - used to belong to the lord of the castle and his family. Now used by the high priestess
- treasury
- war room
- dining room (quite high, but that allows it to be next to the ballroom, which needs to be this high to have big windows above the castle wall level.)
- ballroom, converted into the main temple chamber, for group prayers and rituals.
- attic entry - the attic contains the magic item that maintains most of the main building defenses.

[Braininthejar2]

so, I have the crypts and the main tower left to map.

Is there anything more I could add /should use for flavor?

I'm thinking of adding several corridors that are extra-dimensional spaces, allowing locals to take shortcuts, while confusing intruders.

Beyond the servants, the cooks, and a curst butler, the staff of the main building would consist of the high priestess, several other clerics helping with the rituals, and a bunch of Black Fingers she's summoned to the fortress, anticipating the party's arrival. In case of a fight, she will make a stand in the main hall, or the ballroom, summoning some monsters to weaken the party before going all in with her elites. She has a setup in the main tower that keeps her body safely in stasis, while she uses astral travel - so if she's killed, she'll just come back to her body, and spend the time the party takes figuring out how to reach her on bringing in some demonic allies for the final battle.

The Crypts:

The crypts were first used for burial, then as a resting place by a coterie of vampires, and now are the temple's new prison and necromantic lab. The main entry is through the chapel, but there might be some shortcuts there too, that only the locals know how activate.

The crypts are dug in two levels - there is only so wide one can spread beneath the castle without hitting a well or another cellar.

- preparation room - once used to prepare bodies for burial
- corpse storage - a room filled with apparently fresh corpses - the whole chamber has a gentle repose effect on it, allowing storage of bodies for later necromancy experiments
- the crypts proper - contain a number of old tombs. This is also where the bodies of the wraiths are buried - if they hadn't been defeated yet, they will swarm into the room if the party disrupts the bodies.
- undead storage - a room filled with skeletons, just standing there in dense ranks when there is no job for them.
- cellblock and torture room - replacing the old prison tower in both capacities. An undead jailer supervises both.
- false crypt - the vampires of the castle used this chamber to safely store their coffins. With them gone, there is nothing valuable in the room - but the defenses have since been upgraded, turning it into a deathtrap for anyone snooping around.
- guard room - a bodak knight in service of Beshaba guards this room, accompanied by a bunch of his spawn born of his previous victims. He's the main challenge on this floor.

lower crypts:
- necromantic lab: used to experiments with new forms of undead. guarded by one of the more successful experiments - a bone naga.
- disposal room: a hole with a disintegration effect, used to get rid of redundant organic matter - also of any curious arms reaching within.
- component room: stores alchemical components, and a large collection of preserved body parts, and failed undead.
- experiment chambers - used to store various undead that are still being worked on. The party can just walk past, but if they start opening cell doors, they might release something nasty.
- summoning chamber - for all the planar ally rituals that would work best without too many witnesses.
- main tower entry - guarded by a pair of iron golems.

Map will be made at a later date:

comments? thoughts?

[Gildedragon]

Well I'd expect a castle like this one to have a chapel. What's it been turned into if the ballroom/audience hall has been turned into the sanctum sanctorum

[Braininthejar2]

It's still a chapel. It is normal for major religious sites to have several places of worship. The sanctum is for big ceremonies that involve the entire fortress, while the chapel is for things like clerics praying for spells.

[Braininthejar2]

MAIN TOWER: The main tower is set on the plain of shadow, overlayed over the castle - it goes through the main building, extending 4 floors over the roof. Unless one of the exits is opened from the inside, it can only be entered through the door at the catacombs level 2

If approached from the prime material, the tower is visible in the section that extends over the roof, but trying to get in results in flying through it - it can't be interacted with, nor planeshifted into.

If approached from the Plane of Shadow, it can be entered if sufficient magic is applied to break through its outer walls, or by tunneling to the level of the basement entry. However, the magic that reinforces the walls also radiates negative energy outwards - it has attracted a pair of nightwings, who will swoop in to attack any living creatures that show up there. Any attack that does pierce more than an inch through the wall will alert the high priestess.

Sublevel 2: Entry. There are spiral stairs in the middle, and some locked rooms around the circumference - they contain enchanted blocks of obsidian that make the outside of the tower radiate negative energy - anyone entering the rooms risks level drain, and breaking a block will cause a powerful negative energy burst.

Sublevel 1: The stairs end here. There is one door leading to a smaller stair up, and a bunch of locked rooms around. Most are used as torture chambers for the high priestess' former enemies - they are magically locked and soundproofed.

1 - a woman tied to a metal throne. She's missing the top half of her skull, and facing a mirror. The magic of the throne keeps her alive, and a greater curse cast upon her rolls back her memory every five seconds - keeping her in a loop of perpetually discovering the sight of her own exposed brain.
2 - a man levitating in an empty room, kept in stasis with his mouth open in a silent scream - the priestess wasn't very creative here: he's under eternal torment spell.
3 - a female curst with her body scarred and decayed-looking, locked in a brightly lit cell surrounded by reinforced mirrors showing a reflection of her as a living, stunningly beautiful woman.
4 - a pitch black room - the darkness seems to be filled with something eelike, that phases through the victim's body, writhing and biting inside her - it's an illussion, but one both very painful and damaging to sanity. If someone does brave the danger, there is a man rolled in a fetal position inside - the room acts like a ring of sustenance, also refreshing the man just enough to keep him at the edge of dying from sleep deprivation - he's tortured catatonic, and will die from shock if taken outside.
5 - a small crypt containing a sarcophagus with two names on it. There is nothing magical there, and the sarcophagus contains the bones of a man and a baby - the high priestess' husband and child, killed in a freak accident when she sacrificed that aspect of her life to Beshaba, trading family life for ascent in political power.
6 - a muscular man impaled on a huge steel symbol of Beshaba - a black finger who tried to betray the high priestess to one of her rivals. He's a curst, under a permanent spell that robs him of some of undead immunities, allowing him to properly feel the pain of his dislocated limbs, and the multiple metal rods going through his body. His torture comes with another curse - one that takes his memory away at sunrise, and gives it back at sunset. - So he starts each morning in sudden agony, not knowing where he is, and what is going on, and at sunset, just as he starts becoming numb to the pain, he suddenly realises that he has been like this for decades, and that his next morning will be the same horrible surprise, over and over.

Ground floor: The room looks like a cave covered in spider webs, bigger than the circumference of the tower. There is a door on the opposite side. The door is metal, and magically reinforced - messing with it activates an explosive trap, and attracts four bebiliths hiding among the surrounding rocks.

First floor: the floor is mostly empty, a large, circular room with a solid column in the middle. Around the room there are mirrors displaying views from various locations - with a proper password, each can be opened as a one way gate to a given location. There are also three doors here - two leading to the stairs up and down respectively, and one that overlaps with the trophy room on the first floor of the castle - if that door is closed, and this one is open, it creates a passage inside the trophy room.

Second floor: There are several rooms here, all empty. detecting magic will reveal nothing. In truth they just haven't been used for anything yet - it was easier to build a tower with more, than add floors later.

Third floor: This is the final line of defense before the priestess' personal chamber. The room is an expanded space, like the ground floor, but instead seems completely dark, with no visible walls, even magical light providing at most ten feet of illumination. There are three monsters there ordered to kill everyone who isn't accompanied by the high priestess - a deathshrieker, and a pair of charnel hounds.

Fourth floor: The floor contains three rooms. One is the high priestess' personal library, containing the tomes she wouldn't share with anyone. The other is a containment room, where she stores cursed items, waiting to be disposed of or delivered to her enemies - a nasty surprise for anyone who mistakes it for a treasury. The doors are constructs - the multiple insane faces sculpted upon them will attack if disturbed, lashing out with extendable, metal tongues.

The third room is not locked. It is the high priestess' personal shrine. The room has a trap - the visage of Beshaba over the altar has a confusion effect in it, that will strike anyone irreverent enough to meet her gaze. Beyond that, the room radiates overwhelming conjuration aura - an epic spell has been cast here, creating a bizarre spatial anomaly, linking the shrine with multiple point in space around Toril. As the result, the shrine in a sense exists in many places at once - regardless of the time of day in the fortress, it is always midnight inside, allowing the high priestess to pray for spells whenever she needs.

Fifth floor: There are two more locked rooms here, with the same kind of construct doors guarding them. One is a small treasury containing the priestess' spare magic items. The other is a magically secured room where she leaves her body when casting astral travel - it won't be there now, unless the players failed to kill her astral form when attacking the castle.

The rest of the floor are her personal chambers, which she uses when inhabiting her real body. (which is rarely) It has a bed, a small pantry with magically preserved food, a bathroom with a decanter of endless water, and a toilet made with a bag of devouring.

Sixth floor: the top of the tower seems to be an open space filled with darkness and roiling mist. There is a giant pentagram embedded in the floor, the place for the high priestess most secret and powerful rituals. If the party has pursued her this far, she will be there, surrounded by as many demons as she managed to summon since the previous encounter. She can control the visibility within the chamber, and will use it to hinder her enemies, trying to separate the party to let the demons focus single targets if she's able.

When she's killed (travelling to a clone body she has set up in another fortress just in case) the spell will unravel, and the room will slowly shrink to it's proper dimensions - a domed chamber of the topmost floor. Breaking through the ceiling reveals a carved block of crystal - a focus maintaining the spatial distortions on the lower floors, and most of the effects protecting the tower walls.