I understand why they decided to replace the rat's regular filth fever with Devil Chills, it's an interesting choice but that's a really nasty thing to do to low-level characters. The DC on devil chills may not be high but recovering requires 3 successful saves in a row and by the time that happens it'll probably inflict some hefty stat damage. I suggest either switching back to Filth Fever or at least increasing the rat's CR to ½.
I replace the fiendish darkmantles here with a single fiendish Hyena, rooting through the garbage and scraps for anything edible. This drops the EL of the encounter to 1.
The encounter conditions here are Distracting Visions (which should have a rating but doesn't) or Extreme Cold, but no explanation is given in the text nor any way to tell how or why it would switch from one to the other. I suggest ignoring it.
Again we've got some fairly random encounter conditions. Drafty is fine (although it's never addressed in the room description). But it also apparently is full of noise (Echoes 2) but no indication is given as to where it's coming from or what the noise is. So ignore this.
Another completely random and unexplained encounter condition: concealment (what exactly is blocking vision is never explained). Ignore it. Now ability score damage is annoying at the best of times but when you're trapped in a dungeon at low-level it's really no fun. Let's replace these stirges with a group of four Fiendish War Dogs (big, scary looking mastiffs) worrying at an orc or kobold corpse.
So, again we've got some completely random encounter conditions (Drafty or Poor Footing 2) with no indication what causes one or the other. I'd recommend ignoring both. You've got an ogre fight already, don't make them fight him in darkness and Poor Footing is a pretty clunky and questionable mechanic anyway.
More senseless encounter conditions. Haunted might make sense if the pillar's illusions ran wild or brought PC dreams to life (which would be pretty cool). However that's not how the thing functions so unless you want to make that change I'd remove Haunted.
Given that I'm excising most of the darkmantles from this adventure you might change the description to other fiendish critters, or you might keep the darkmantles in to give a sense of the bizarre.
Again, poorly done encounter conditions. This place supposedly has Distracting Visions, but it's never given an explanation or a rating. Ignore it.
Turag is a fun encounter and one of the reasons I consider Region A to be worth saving. However we've got more random encounter conditions. Apparently this room grants both cover and concealment...but why? Is it full of trash or furniture? Rubble? Who knows, ignore the conditions.
Again, I'd recommend switching to a mundane rat swarm, if for no other reason than it's going to be a headache to figure out how to properly stat a swarm with the fiendish template (and if you do it by the book the DR is going to make it essentially unbeatable).
This region is going to be really tough on the PCs since they're constantly sickened. The text here tells you that there are certain rooms where they'll have to save or be nauseated but this doesn't really make any sense since most of these rooms are empty and many are not even places where there are a lot of troglodytes. So ignore that. It's a terrible idea considering the PCs are already sickened.
The only upside is that the PCs will be well aware that they're under penalties and if they're smart they'll be cautious or avoid this area.
This section is also a mess even by the low standards of the WLD, rooms are referenced wrong all over the place, ELs are completely inaccurate. It's pretty awful. One major one is that there are two A33's
Again we've got Distracting Noises without any rating or explanation. Ignore it. Now, we've got 8 fiendish stirges which is quite an encounter even if they only will drain 2 con each. If you feel your PCs are up for something this big then go ahead and throw them into it, but I'd recommend cutting the number of stirges in half. (personally I'd replace them with something more interesting too like a Fiendish boar or monitor lizard).
This area has the “decrepit” encounter condition which does not seem to actually exist (man the editing is horrible in this book). It's also got some completely nonsensical backstory to the room involving torture and slaves (neither of which make sense given the dungeon's history). Apparently even though it's described as being free of stench this is also one of the places that may cause nausea. I'd remove this pointless room entirely.
Hell's bells...this is a deathtrap here. It's also terribly described. The encounter actually takes place in a hallway that's several doors away from room A33, and claims that there are troglodytes stationed in rooms A1 (the one full of stirges) and A2 (the trapped secret room). It's just a mess. This whole thing needs to be redone.
First and foremost it's far too deadly. There are six troglodytes who are in prime strategic positions, difficult footing for the PCs and on top of it all they're sickened. The easiest way to make this better is to have the troglodytes challenge the PCs as they approach. Put the two “floating” troglodytes (the one the encounter claims are in the rooms where they couldn't be) in the middle of the hallway as watchmen with the other 4 hidden in the alcoves as backup. The PCs have the opportunity to retreat or attempt to be diplomatic and if they rush in and fight at least they're doing it on their own terms.
There are two A33's. The first one seems to be referring to the hallway on the map marked with A and B's. This second A33 seems to be referring to the the chamber on the map actually marked as A33. This is also apparently where one of the “floating” troglodytes was meant to be.
This encounter is fine, but they've got the CR and ELs all messed up. The EL is listed as 2 but Yrkak alone is a CR 3 enemy (although the stats have him incorrectly listed as CR 4). Even wounded and fatigued the other trogs probably bring this up to EL 4 at least.
The wounded Trog's stats also don't accurately reflect the fact that they're fatigued. Remember they suffer an additional -1 to attack, damage, AC, initiative, and so on.
This area is worth noting if for no other reason than it has a encounter condition that actually seems appropriate.
This room is more than a little confusing. Two secret doors and a trap to hide a small supply of completely mundane weapons? I'd suggest having most of the weapons here rotted and useless, but this is a good place to drop some magical supplies. Perhaps a cache of mysteriously unrotted missiles (say some +1 arrows or bolts) or some well-preserved silver arrowheads. My personal suggestion: quiver (20) of +1 shocking arrows or bolts. It'll make a big difference in their survivability. It's also apparently extremely cold and drafty for no apparent reason. Keep or ignore those conditions as you wish. I don't see any reason to add the extra complexity though.
Since all the furniture in this room is wood I don't see why it's considered “soft” cover. In fact checking the SRD soft cover only comes from other creatures. Change the encounter condition to Cover.
Amusingly this room, although empty, is apparently “hostile”
I'd waive the Craft Magic Arms and Armor requirement here. For one thing it's not something PCs would have until 5th level. Just let them try and complete the enchantment and if it works then bam, decent magical weapon.
The EL here should be 2, not 1.
Again, more worthless encounter conditions. The Distracting Noises again have no rating. Chuck 'em. They're worthless anyway. Concealment might be justified by the large amount of debris, but it's worth noting that the previous chamber had plenty of wreckage in it too and it didn't have that condition.
Also, am I the only one getting bored of fiendish dire rats? In fact this room is basically the exact same as A41. It's got a collection of dire rats, which don't want to fight and instead try and look buff and scary (although for some reason the DC to recognize this is higher in A42 than A41). How about a Large Fiendish monstrous centipede clinging to the ceiling or hiding under debris.
Again we have the Decrepit encounter condition. I'd say this is a good place to put some silver weaponry for the PCs. Perhaps Borryn didn't trust Longtail and wanted some insurance. Perhaps he has a silver speartip on his body or a silver dagger or short sword in his personal chest.
Now, it's hard to say at this point what levels the PCs will be. They could have wandered just about anywhere so they could have stumbled this way while still level 1 or they might be level 2 or even three. However, remember how I said that rat swarms were dangerous, especially fiendish ones. Now the PCs have to fight two of them. I'd say either have the swarms stay here, feeding (so the PCs can choose whether or not to bug them) or make it just a single swarm. Or even better, throw something new at the PCs. How about a pair of fiendish Leopards or a Fiendish Tiger if you think they're ready (EL 4 which is what this encounter claims to be. But two CR 3 critters are actually EL 5).
Replace this nearly impossible-to-find (DC 30) trap with a Javelin trap. In fact, make it a silver javelin. This place was meant to hold demons and devils after all and it's a good way to give the PCs fodder against longtail. I'd probably recommend making all the major bladed and arrow traps silver or cold iron.
This place apparently has either Distracting Noises (with no rating again) or haunted. But again no indication of why or which one should appear. I say, again, to ignore them. They add nothing.
This chamber is apparently Drafty, but putting out the player's torches seems pretty pointless when there's no enemies and a giant glowing crystal. I personally would have the minor demon still imprisoned in the crystal. It gives a hint as to the nature of the dungeon rather than making it just a bizarre dungeon feature.
This room is one of those oddities in Region A that doesn't fit with the rest of the dungeon or it's backstory. This room also has no encounter conditions despite being one of the few places where things like distracting visions or haunted might be appropriate. It's also got an extremely unfair “curse” that hits you whether you save or not if you touch the throne.
I'd recommend ignoring this room or replacing the throne with a demon skeleton in chains. The thing's long dead but the lingering evil can still curse those who handle it's bones (but the save negates the curse).
A53 and 54
More random, unrated encounter conditions. There's so many of these things.
This room has the encounter condition of Deeper Darkness...that's random and it's not reflected in the description of the room at all. It doesn't even take this into account when saying that the darkmantles should be easy to spot. This condition might be worth keeping...but the darkmantles sure aren't. What's a good monster to fight after stumbling into a room of deep darkness and gloom...How about a Fiendish Dire Bat (EL 3)?
Ignore Poor Footing (it's not a good mechanic) and instead just treat the room as difficult terrain. Here's a couple of extra large Fiendish darkmantles. I'm going to go ahead and let these guys stay darkmantles.
The PCs will definitely be happy to find these continual light batons. While you're at it, make them out of silver. It'll reward clever PCs who realize that they could be effective weapons when they face longtail.
Encounter Conditions seemed like a good idea, but they're worthless unless they have some context. The Cover condition works fine, but what is providing the concealment? That's a big deal because it's going to determine what effects can be used to bypass it. I'd say keep the Cover but ditch the Concealment.
First there's some mistakes in the stats here. The 4th kobold warrior is apparently (at least based on his HD and attack bonus) a third level warrior. The whole encounter is at least EL 6 as well and probably closer to 7.
That said, I'd say this is a fair encounter. The kobolds aren't going to chase the PCs down and murder them and they're fairly open to negotation. Players who take a “murder them all right now” approach will regret it but it's still a decent encounter. However, Boykit himself definitely needs adjustment. First and foremost although the dungeon designers claimed they didn't allow anyone to have web/entangle/etc. Boykit does and since he's a wizard it'll be in his spellbook too. So decide if you want to avoid your PCs getting ahold of that (perhaps replace it with Bull's strength that he can cast on his warrior or the krenshar or False Life to bolster his pitiful hp). His combination of Color Spray and Sleep also has the potential to be pretty devastating. I'd recommend switching one of those out with a second Magic Missile spell.
I don't really know what the point of a Color Spray trap is, especially in a dungeon meant to imprison powerful outsiders. Let's “refluff” this as a special spell to defeat evil outsiders which just happens to function as a color spray against mortals. There. Lets say it inflicts 2d4 divine damage against evil outsiders, if the players can work out this property they might be able to make use of the trap against the various fiendish critters.
This room is apparently full of fog. Although you wouldn't know it from any of the room's descriptions. Perhaps it's meant to represent dust (despite none of the other full-of-dust rooms having this property)? We'll give it the benefit of the doubt and say that's what it's meant to be. And look, another fiendish rat swarm. Oh boy! Lets make it more interesting and make it a trio of fiendish wolves or hyenas. That would make an EL 2 encounter (which is what this falsely claims to be.
Replace this magical scorching ray trap with a pair of simultaneously triggering basic arrow traps which fire one silver and one cold iron arrow. The trap has 2d6 shots left before it's exhausted. According to the encounter conditions the room is also full of smoke but again there's no indication in the room's description. Ignore this condition.
22 freaking fiendish Stirges. Fortunately they're not concerned with the PCs and can easily be left alone...but damn that's still a lot. My suggestion is to drop the number to a dozen (which is more than enough to represent a major challenge) and let the PCs decide for themselves whether they're tough enough to tackle this group. The “ring of warmth” is a ring of minor energy resistance (cold).
The first encounter with the orcs is going to turn really nasty. The description claims this is an EL 6 encounter. That's a filthy lie, this is EL 8-9 and the player's will get their faces murdered if they try and take on the orcs head on. If your group has significant backup (say Boykit and his crew) then you might try and keep things as is, but if they're by themselves and you don't think they'll try and parley you'll need to severely nerf these guys or you'll be faced with several PC deaths.
First, drop the Orcs to level 2 warriors (-2 to attack due to lose of BAB and weapon focus, and -4 hp). The Orc barbarian alone is a big challenge so either drop him a level or turn him into a basic orc warrior 3. Even with these changes this is still a nasty encounter but there is opportunity for retreat and negotiation.
Also worth noting that the stats for the orc barbarian's AC is all wrong (somehow it's 15 base with only studded leather and 11 dex, 10 touch, and 13 flat-footed. There's no combination that makes this work). His AC should be only 13 like the others.
In this encounter, always make sure the orcs hesitate. If the PCs are swarmed by the orcs and Orghar then they are basically doomed. Orghar alone is enough to take out a group of low-level PCs all by himself and he's more than enough challenge for them right now.
Orghar's battleaxe only inflicts 1d8+4 when it should be 1d8+5 (+7 when raging).
A fireball trap? Against PCs of third level (and quite possibly less)? Seriously?! That's an average of 21 damage on a failed save which is well above the average hp of most third level PCs. And it protects a completely empty room. Now I have no problem with the idea that there might be traps that protect nothing in this dungeon. It provides a good sense that there's something odd about the place and that it was created for purposes now lost. But seriously, this trap could kill PCs stone dead and they end up with a reward of absolutely nothing. They don't even provide a description for the room. It's just a slap in the face.
My suggestion? Ditch the fireball trap completely, but keep the burned corpses. The trap has finally reached its limits and doesn't work anymore. Good way to keep the players on their toes but it's not going to blow anyone to hell. Also, they refer to room A38, they meant room A83.
What is even the point of this room? Sure something like this makes sense in a “mad wizard” dungeon like the tomb of horrors where it's basically just someone's personal funhouse of doom. But why is there a box full of poison spores on a pillar in the middle of this room? It's not even something that would inconvenience most of the creatures the dungeon was meant to hold and it's certainly not a convincing trap.
Just to make it interesting, let's actually put something in the box. It's built to hold a minor evil artifact: a darkskull. Rather than being carved of ebony this variation is made from a severed head, eternally rotting (and host the the colony of yellow mold). The box contains the Unhallow effect of the darkskull. It is attached firmly to the pillar and it was locked (an unfortunate orc broke the lock and got a faceful of mold for his trouble.
Again we have some truly bizarre traps here. The WLD was built to hold undead and demons none of which can be affected by a Sleep spell and would probably not even be mildly inconvenienced by a Flare spell. Even if the traps were meant for humaniods how is a sleep spell meant to act as security? My suggestion is to remove the darkmantles entirely and replace the Sleep and Flare traps with a 2nd level Shocking Grasp trap. Very difficult for low-level rogues to remove but there's dozens of ways to get it off the trapped pedestal without touching it directly. There were originally alarms and other wards protecting the knife but repeated attempts to steal it have slowly worn them away.
This is one of the most bizarre rooms in Region A. There's a secret door here hiding what appears to be a massive garbage pit...but where did the garbage come from? The humanoids certainly didn't bring it here (it's far too much and it's nowhere near any of their camps) and the dungeon's original builders didn't have any need for garbage pits. Even if you assume it was used as a garbage dump by some squatters before longtail showed up how has the garbage not fully decomposed? And, considering the whole thing is behind a secret door, how did all of these rat swarms get in here?
With the sheer number of rats (more rats!) and the sickening effect of the garbage and the fact that a torch brought into the room will cause it to blow up this is easily one of the more dangerous encounters the PCs could face and it serves absolutely no purpose. I say simply ignore this section of the map entirely.
Again with the high level magical traps! This door is already trapped and the PCs are unlikely to check for a second trap (and unlikely to find it given the DC for magical traps). The lightning bolt is more than enough to kill whoever steps through the door and serves no purpose beyond trying to murder PCs. Ditch it and just keep the blade trap. This room is another good place to drop some magical ammo for the PCs (magical ammo is a good way to give them effective weapons that will still be exhausted) maybe some +1 silver sling bullets (anyone can use em).
Again, creatures in this room have concealment for no clear reason. Ignore the useless encounter condition. And why not replace the overused fiendish darkmantles with a big creepy web with 4 Fiendish Medium Monstrous Spiders. Give their web the same energy resistance as the spiders and watch when the PCs panic as their fire spells do nothing to burn down the webbing. Heck, lots of webbing might actually justify concealment for once.
This room grants both concealment and cover...even though the debris is on the floor and the darkmantles are on the ceilings. Also...the treasure is listed as “Ambush (darkness)” which is another encounter condition. You could throw more spiders and webs in here if you like or just about any other fun fiendish critters.
More darkmantles...but bigger!! Replacing creativity with more HD! Well, at this point I've removed enough darkmantles from the dungeon that you could keep these guys and it might be a marginally interesting encounter. However, it's way too tough for most parties. They lie on the EL again (it's actually EL 7) and five darkmantles with greater strength are enough to really rip up an unlucky team of adventurers. Limit this to 3 and it works (that's an actual EL 5 encounter) or just one or two if the PCs are badly hurt or low level.
Oh dear...I may just weep. More darkmantles...now they're 3 HD! Oh and there's seven of them! Not only is this encounter terribly balanced but at this point there have been 4 rooms in a row that are nothing but darkmantles in increasing numbers and size. What is even the hell. Here, how about we just go all out. A darkmantle king! A single, medium-sized half-fiend darkmantle.
Medium Outsider (extraplanar); CR 5; HD: 3d10+9; HP: 29; Spd: 20 ft, Fly 30 ft (poor); AC: 18, Touch 11, Flat Footed 17; Base Atk: +3; Grp+10; Atk: +10 melee (1d8+7, slam plus grab) +1 melee (1d6+3, bite); SA: Darkness, Improved Grab, Constrict (1d8+10), Smite Good 1/day; SQ: Blindsight 90 ft, Immune to poison, resistance 10 to fire, acid, cold and electricity, SR 13, DR 5/magic; AL: NE; SV Fort +6, Ref +4, Will +1; Str-24, Dex-12, Con-17, Int-6, Wis-10, Cha-12
Hide+11, Listen+10, Spot+10, Move Silently +4, Knowledge (planar) +1, Survival+3; Improved Initiative, Improved Natural Attack.
Now that's how you make a !@$%ing interesting darkmantle encounter!
There's...more...damn...darkmantles. DAMMIT! WHY!? Anyway, these are sad, emo darkmantles with no self-confidence. They know they shouldn't exist. So write them out of the WLD. Make this a nest instead, an Alien-esque hive where there are dozens and dozens of darkmantle eggs, big transparent globules with tiny squids inside. It's clear if the PCs don't kill them now they'll soon hatch and completely overrun the dungeon. They'll be darkmantles everywhere! Kill them! KILL THEM NOW!!
Also apparently this room is very scary for some reason. Perhaps the thought of a dungeon full of nothing but darkmantles shakes the PCs to their core?
Here we've got another magical trap (one quite capable of being deadly to low level PCs) that's guarding nothing at all. Imagine getting a character killed by this trap and the other PCs drag off your corpse and manage to get to the chest only to find nothing. That's just a big middle finger to the PC. Either keep the empty chest and remove the trap entirely (but show that it did once exist) or make the trap the treasure. A pair of scything blade traps, one cold iron and one silver. They can be reffitted as battleaxes (DC 15 craft (weaponsmithing) a failure ruins the blade) if the PCs are clever enough to think of it.
Again a trap that seems totally useless for any actual purpose. Hold Person won't do any good unless combined with an alarm or other trap. Since this trap serves no purpose, remove it. Also remove the completely unaddressed fog that apparently fills the room.
The fire trap here is actually fairly justified and it's hardly deadly enough to kill anyone so keep it as is. The room apparently has “soft cover” but that's never explained (despite the fact that it's quite big there is actually no description of the room and its contents).
The encounter claims it starts as “indifferent” but considering the lizardfolk open up with a volley of arrows and a flaming sphere I doubt the PCs are going to feel like talking. If you actually want this to end without violence it's probably best to have at least one of them shout “Go away” in draconic or orcish before they start shooting.
Since these guys have some clue as to Longtail's nature they're a good source of clues and possible silver weapons. Perhaps Kalhiss has been sharpening silver coins into crude arrowheads (-2 to hit, -1 damage, but still counts a silver).
Another lone trap that serves absolutely no purpose. Remove it! It does nothing and it guards nothing. Have a false-alarm trap instead. One of the PCs steps on a hidden pressure plate and a slot opens, coughs and sputters and disgorges some gooey wads of black tar before shuddering and sliding shut.
A pointless trap and an unrated, undescribed Distracting Noises encounter condition. Worthless. Let's replace this with something cool...lets see...Longtail and his familiar stopped here trying to find the chapel. To properly commune with the infernal powers the imp required the sacrifice of one of the orcs. He's bound hand and foot to the floor and covered in marks of horrible torture and demonic magic. A DC 20 Knowledge (religion) or (planes) check lets a PC recognize the symbols as demonic ritual magic.
Despite being far, far away from anyone doing anything this room is apparently full of noise (-6 to listen checks according to the encounter condition). Other than that it's a waste of map-space Let's try and actually make this one interesting, using the weird properties of the dungeon. Remember A98 where the orc was tortured? Well as the PCs are leaving that room they hear a faint noise. Following the noise (which gets louder) it leads them to this room. It's the sound of the orc begging for his life and finally dying, caught in an endless echo by the dungeon's malfunctioning magic. After the orc's whimpers die away your PCs can catch bits of sniping between longtail and his familiar, possibly granting some actual insight into this bizarre place. The exact details should depend on what you want to reveal and how far the PCs have progressed.
An owlbear fight. A fiendish owlbear fight in fact. This certainly isn't the toughest fight in the dungeon and if your PCs have some magic weapons (unlikely considering the only ones I can recall have been orghar's axe, the dagger of venom and the shortsword in the exploded smithy) or several NPCs as backup then they probably stand a pretty good chance in this fight. However, if they don't have backup or aren't fully rested then they're probably going to get ripped up pretty bad. In fact, looking at this map the owlbear is just down the hall from longtail. Even if the PCs survive this fight it'll mess them up and if they aren't careful the next encounter they stumble into could be longtail himself.
Ultimately I'd say it's a matter of how many PCs you have, how well supplied and rested they are and if there are any NPCs to help out. You can probably keep the owlbear but I'd recommend switching to a regular Fiendish brown bear or fiendish dire wolf. Both are good encounters and are more survival friendly.
You know I was thinking that this might be better going in front of the owlbear (or bear or dire wolf) fight to give the PCs some warning...but the more I look at the map the less sense this makes. The owlbear is hanging out right down the hall from longtail. How have the two of them avoided fighting? I'd suggest giving the Chapel a good hefty double door, perhaps with some ominous carvings. A good “boss fight here” indication so the PCs can be cautious and possibly even rest first. Not locked but strong enough that it can't simply be smashed through.
Here's the chapel and longtail. I'm kind of conflicted here so let me break things down. First, if you follow longtail's tactics as described he comes off as incredibly dumb (casting expeditious retreat instead of fly to prepare for a dangerous encounter and simply opening the door and attacking instead of using invisibility to size up his opponents). However, dumb or not this encounter is incredibly poorly balanced.
Let's see, first we've got the at-will invisible flying, poisonous imp. Played properly he's annoying and almost impossible for PCs to deal with (although they could probably make him flee he'd hit many of them with poison and probably the most vulnerable ones).
Second we've got longtail himself. A 7th level sorcerer would be a pretty insane boss for a group of (presumably) 2nd-3rd level PCs. But on top of that he's a wererat!?
He's a CR 10 enemy (which for some reason is described as EL 7? what?). The only thing that prevents Longtail from being a horrible nightmare encounter is that the writers seemed to have made every horrible choice possible. His spells are, for the most part, awful. He has a Craft Wand feat (but his only wand is for a spell he doesn't know) and is actually missing a feat he should have from being human and the suggested tactics are basically trash.
However, even with all that going against him he's a nightmare for low-level PCs. He can turn invisible, fly and (with shield) has AC 23 and DR 10/silver. By the way, the only silver weapons in the entire dungeon are a few daggers in room A114 and he's supported by his poisonous, fast-healing, flying imp. Even though magic missile is literally his only offensive spell he can pound out 6 first level spells a day after shielding himself. He could easily take down the low-hp party members with magic missiles alone (while his imp hangs around invisible to take opportunity attacks on spellcasters) then use sleep and his color spray wand to pound the remaining PCs into unconsciousness and kill them at his leisure. All while flying through the air basically immune to their attacks (the PCs can't afford either silver arrows or strength-damage longbows so the only ranged attacks that might affect him are magical or the rare critical hit...and he's already shielded so magic missile is right out).
Now the longtail fight is going to depend a lot on whether you've given your PCs magic weapons, whether they're well rested, whether they've got backup and so on. So instead of providing a definite “do this to balance things” here are some general suggestions.
First, make longtail an infected rather than natural lycanthrope. I'm shocked that the WLD designers didn't do this in the first place. It drops his DR to 5/silver (enough to make him tough but not so much it makes most attacks useless) and it means he can't infect any of the players with lycanthropy.
Second, drop his sorcerer level to no more than 5. This way he won't be flying around the room out of reach of everyone and forces him to use some actual tactics. This also means he's no longer missing a feat. But just so it's not stupid, drop Craft Wands. Even Toughness is better for longtail.
Third, have him actually talk some. I don't mean try to parley. He's still a boss fight so he's going down. However, it helps to get rid of the element of surprise. Perhaps he'll try to talk the players into jumping into the portal, masquerading as some invisible guardian spirit. Telling them “it's the only way to close it!” (longtail may or may not know it will close it, perhaps he things it's a way to finally take control!)
The fourth I've already been doing. Drop some silver equipment around the dungeons, at least give the PCs a chance at bypassing his damage reduction. If they've allied with the other humanoids then they might already know he's a wererat and be ready for him.
Here we've got another fireball trap. You know, there's been about three high level spell traps (fireball, lightning bolt) already and like this one I don't think any of them actually are guarding anything, yet they're quite likely to kill PCs. Thankfully this one actually is protecting some useful gear but I still say it's too strong and has got to go, but the loot here is deserving of some decent protection. How about a CR 4 poison dart trap? That seems a good balance.
This room's certainly interesting, although it really has no reason for existing but I'm sure it's a welcome aid to PCs. However, you may notice that a Chaotic Good character will apparently suffer damage and heal damage at the same time. So why not just have nothing happen?
This room actually addresses the encounter conditions as part of it's description (well, other than negative energy. But two out of three is better than most of the rooms so far).
More actually relevant encounter conditions! It's amazing! Again, just go ahead and don't do anything for chaotic good characters. I'd also suggest ignoring the fact that it supposedly grants a permanent benefit to lawful good characters. That's just not fair to anyone who choose to play a different alignment.
Pointless but interesting I suppose. But still, amazingly more actually relevant encounter conditions. They're on a roll...after 100 rooms.
The description for this room is just terrible (and apparently it has spell resistance for no real reason) but I think it's meant to imply that the space between the two pillars is full of gigantic (25 feet long apparently) blades? That seems silly, especially considering there's gaps around the pillars that easily allow you to walk past. I'd just ignore the room's terrible description. Have a skeleton or two impaled on a rusty trap in one corner and leave it at that.
See my suggestion for room A108.
Why can these people not seem to settle on a way to imprison demons? And why does this supposed prison have an entrance and exit with no apparent lock or restriction? Also the writers of the WLD seem to constantly fail to realize that outsiders actually need to breathe. This room contains the only silver weapons in the entire region and getting them requires fiddling around in an airless void with some orc corpses and a DC 20 search roll. So it's not exactly easy.
So, this is a horrible travesty of a prison that doesn't actually seem to serve any purpose. So here's my suggestion. The big cube of basalt remains, one one side is a small diamond-shaped bronze plate. If touched the cube becomes transparent as long as someone's hand remains on the plate. The cube is full of Lemurs, packed in so tight that there's no room at all, just a single mass of horrific demonic flesh and tortured faces. Seeing this has the effect of a Scare spell but it is impossible for the lemurs to escape.