I'll try to contribute, if there's alredy a Scrying Room and I missed it please feel free to discard everything (I couldn't read all the posts in such a messy order, I've been following the best I could, sorry for that

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Also I couldn't add the CR for the encounter since I am not very familiar with the "advanced monsters" CR nor with the CR system (I usually grant AD Hoc experience based on how the encounter went).
As for the Scrying spell, the book says that for the Arcane Version you need a Mirror, I decided not to add the mirror and let the wizards cast it from the Font but if you feel it's a big "house rule" feel free to add a mirror in the room, I won't get mad

Also my english is really bad, so if anyone wants to "embelish" something or correct my spelling or anything I'llbe more than grateful.
Well enough talk here goes my attempt:
19 - Scrying Room
The walls in this room look rather dark but with proper lightning you can see that they cast a small reflection, kinda like the one an old dusty mirror would give. The room has some ebony shelves filled with glass jars and bone scrollcases. In the middle of the room is a large font with some Abyssal runes. Two monk like figures are standing in each of the northern corners, facing the door, looking down and clothed with large robes and hood covering their heads.
The jars contain the Arcane Material Components that are necessary for the Scrying spell, that is hawk and eagle's eyes, and maybe some roc eyes too, as well as nitric acid, copper and zinc. The scrollcases contain three arcane and three divine versions of the Scrying spell as well as three arcane and three divine versions of the greater scrying spell.
The inscriptions in the font read "The Eye of Blasphemy" and the font itself is filled with unholy water.
The "monks" are actually two Permanent Images left there to discourage any trespassers and to "decorate" the room. The real guardians of the room are two Advanced Invisible Stalkers (12HD) that attack anyone who enters the room and was not authorized by Blasphemy himself (The residents of the Dungeon are allowed to get in as are eventually some visitors). The Invisible Stalkers are bound to serve Blasphemy fro ten years guarding the room, when the 10 years are over Blasphemy will call new ones (or maybe change the guards for the room, as a Chaotic creature that can't really be predicted)
ADVANCED INVISIBLE STALKER
Large Elemental (Air, Extraplanar)
Hit Dice: 12d8+24 (78 hp)
Initiative: +9
Speed: 30 ft. (6 squares), fly 30 ft. (perfect)
Armor Class: 18 (–1 size, +5 Dex, +4 natural), touch 14, flat-footed 13
Base Attack/Grapple: +9/+17
Attack: Slam +13 melee (2d6+4)
Full Attack: 2 slams +13 melee (2d6+4)
Space/Reach: 10 ft./10 ft.
Special Attacks: —
Special Qualities: Darkvision 60 ft., elemental traits, natural invisibility, improved tracking
Saves: Fort +8, Ref +13, Will +6
Abilities: Str 18, Dex 20, Con 14, Int 14, Wis 15, Cha 11
Skills: Listen +19, Move Silently +20, Search +17, Spot +19, Survival +2 (+4 following tracks)
Feats: Combat Reflexes, Improved Initiative, Weapon Focus (slam), Alertness, Great Fortitude
Alignment: Neutral
An invisible stalker attacks by using the air itself as a weapon. It creates a sudden, intense blast of wind that pounds a single target on the same plane as the creature.
An invisible stalker can be killed only when it is on the Elemental Plane of Air. When performing a task elsewhere, it automatically returns to its home plane when it takes damage sufficient to destroy it.
Natural Invisibility (Su): This ability is constant, allowing a stalker to remain invisible even when attacking. This ability is inherent and not subject to the invisibility purge spell.
Improved Tracking (Ex): An invisible stalker is a consummate tracker and makes Spot checks instead of the usual Survival checks to trace a creature’s passage.
Elemental Traits: An elemental possesses the following traits (unless otherwise noted in a creature’s entry).
—Darkvision out to 60 feet.
—Immunity to poison, sleep effects, paralysis, and stunning.
—Not subject to critical hits or flanking.
—Unlike most other living creatures, an elemental does not have a dual nature—its soul and body form one unit. When an elemental is slain, no soul is set loose. Spells that restore souls to their bodies, such as raise dead, reincarnate, and resurrection, don’t work on an elemental. It takes a different magical effect, such as limited wish, wish, miracle, or true resurrection, to restore it to life.
—Proficient with natural weapons only, unless generally humanoid in form, in which case proficient with all simple weapons and any weapons mentioned in its entry.
—Proficient with whatever type of armor (light, medium, or heavy) that it is described as wearing, as well as all lighter types. Elementals not indicated as wearing armor are not proficient with armor. Elementals are proficient with shields if they are proficient with any form of armor.
—Elementals do not eat, sleep, or breathe.