Just tossing a quick thought into the mix here.
Quilp'thoth, Blight of the Soul
Rising out of the slain body of the decadent noble is a black, mist-like shape, slowly forming two large, ink-black wings like that of a bat, a thin, emanciated body and two arms ending in long, ridged talons. The most horrific feature, however, is the head, crowned with a mane of writhing, segmented legs like a crabs, in the middle of which sits a single eye of burning green flames that glares out at you over a mouth full of needle-like teeth outlined in the same unholy flame.
"A pity" the creature hisses, staring down to the man you had just slain. "I enjoyed that vessel. Ah well, it was getting too old to be of much use anymore, and I think one of you will do just fine as a replacement!"
Howling like a banshee, the shadowy beast lunges forwards, passing through the debris of the previous fight like mist as it closes in on you with talons outstretched and a cruel set to it's expression
(note this monster was built by adding extra HD, not the Simple Template Advanced Creature)
Elder Shadow Demon
XP 12,800
CE Medium Outsider (Chaotic, Demon, Evil, Extraplanar, Incorporeal)
Init +8; Senses Darkvision 60 feet.; Perception +20
[Defense]
AC: 19, Touch 19, Flat-Footed 15
HP: 76 (9d10+27)
Fort: +6, Ref: +12, Will: +8
Defensive Abilities: Incorporeal DR 10/Cold Iron or Good
Immune Cold, Electricity, Poison: Resist Acid 10, Fire 10, Spell Resistance 19
Weaknesses: Sunlight Powerlessness.
[Offense]
Speed: Fly 40 feet (Perfect)
Melee: 2 Claws +13 (1d6 plus 1d6 cold), Bite +13 touch (1d8 plus 1d6 cold)
Special Attacks: Pounce, Sprint, Shadow Blend, Possession.
Spell-Like Abilities: (CL 11)
At Will: Deeper Darkness, Fear (DC 19), Greater Teleport (Self only), Telekinesis (DC 20).
3/day: Shadow Conjuration (DC 19), Shadow Evocation (DC 20).
[Statistics]
Str - Dex 18, Con 17, Int 14, Wis 14, Cha 20
Base Attack +9, CMB +13, CMD +23
Feats: Blind-Fight, Combat Reflexes, Improved Initiative, Lightning Reflexes, Ability Focus (Possession)/
Skills:[/b[ Acrobatics +16, Bluff +16, Fly +22, Knowledge(local) +14, Knowledge (Planes) 14, Perception +20, Sense Motive +16, Stealth +16.
[b]Racial Modifiers: +8 Perception
Languages Abyssal, Common; telepathy 100 ft.
[Ecology]
Environment any (Abyss)
Organisation Solitary
Treasure Standard
[Special Abilities]
Sprint (Ex): Once per minute, Quilp'thoth can increase its fly speed to 240 feet for 1 round.
Shadow Blend (Su): During any conditions other than bright light, Quilp'thoth can disappear into the shadows as a move-equivalent action, effectively becoming invisible. Artificial illumination or light spells of 2nd level or lower do not negate this ability.
Sunlight Powerlessness (Ex): Quilp'thoth is utterly powerless in Bright Light or Natural Sunlight and flees from it. When caught in such light, it cannot attack and can take only a single move or attack action.
Possession (Su):This ability acts similar to the Magic Jar spell but applies indefinitely, and the target must take 2 will-saves, one to resist the effect and the second to notice the possession. Once inside a 'host', Quilp'thoth cannot be detected by Evil or affected by spells that would banish him unless they would also affect the Host. Once Quilp'thoth has control of the 'host', at any time he can usurp control of the body and use it as his own, effectively rendering the 'host's consciousness into a coma-like state until such time as he reverts control back to the 'host', whom have no memory of their actions while under the Elder Shadow Demon's control.
While possessing a target, Quilp'thoth cannot use any of his special-abilities but can use his spell-like abilities. While struck by Sunbeam or Sunray, Quilp'thoth is driven out of his 'host' and takes 2d10 points of damage.
Quilp'thoth can perform a Possession a number of times per day equal to his Charisma Bonus, and requires a touch-attack to activate the ability. Quilp'thoth can do this while invisible or using his Shadow Blend ability.
PCs could encounter Quilp'thoth as the true puppet master behind a criminal empire or corrupt order of Nobles, possessing the leader of a formerly genteel and altrusitic organisation and slowly twisting the order to becoming cruel and self-empowering.
Extremely selfish, Quilp'thoth was banished from the Abyss for a failed coup against a minor demon lord, and as such has lost the ability to call upon other Shadow Demons. In the centuries of his exile on the Material World, he has refined his abilities to become a master possessor, being able to slip inside another being's soul and ride them like a flea on a dog until the right time to take over and use their bodies for his own amusement.
The 'best' way for PCs to encounter Quilp'thoth is by slaying his mortal-'host'-body, likely a CR 7 Noble who has been possessed by Quilp'thoth so long his higher mind has burnt out, meaning that when the Elder Shadow Demon leaves the body, it's reduced to an instinctive level of thought-processes. There is nothing of the person left behind to question or redeem. The PCs have burnt out some of their abilities fighting the Noble (make him a 6th level Noble with a PC's wealth) and now must face an entirely different foe whom they probably were not prepared for.
Even better with Quilp'thoth, is that he can quite simply disappear the first time the PCs get the better of him ... if they can get the better of him. When next they encounter him Quilp'thoth could have set up a situation where he has several 'hosts' available, forcing the PCs to risk killing up to five valued friends or high-ranking public officials or similar, meaning that even if the PCs do manage to slay/drive off Quilp'thoth, their reputation is in shambles as they are accused of attacking the 'innocent victims', whom have no recollection of their actions while possessed.
Dammit .... Possession DC should be 21. Blargh, sorry. *supremeforcefacedesk* I seem to keep screwing up on these boards lately!
Nice elder shadow demon. That could definitely give a party fits. Here's my submission.
Natalia of the Ruined Hand.
Lamia Monk 8th CR 11
NOTE: Read the tactics! That's whats important!
XP 2,400
LE Large monstrous humanoid
Init +5; Senses darkvision 60 ft., low-light vision; Perception +18
Defense
AC 34, touch 24, flat-footed 34 (armor +3, +6 deflection, +5 Dex, +1 dodge, +3 monk, +7 natural, –1 size) ki dodge bonus AC 38, touch 28, flat-footed 38
hp 136/ (9d10+8d8+51)
Fort +17, Ref +20, Will +23 (+2 vs enchantments)
Offense
Speed 80 ft.
Melee touch +20 (1d4 Wisdom drain), unarmed strike +20 (2d6+5), flurry of blows +20/+20/+15/+15 (2d6+5), flurry of powerful blows +16/+16/+11/+11 (2d6+13)
Space 10 ft.; Reach 5 ft.
Special Attacks Ki Pool (10/day, extra attack at highest base during flurry, +20 to movement for one round, or +4 dodge to AC for one round, +20 to acrobatic jump checks for one round, or spend 2 ki to heal 8 hp), Stunning Fist (DC 24 stunned or fatigued for one round or sickened for one minute 12/day) Wisdom drain
Spell-Like Abilities (CL 9th)
At will—disguise self, ventriloquism
3/day—charm monster (DC 16), major image (DC 15), mirror image, suggestion (DC 15)
1/day—deep slumber (DC 15)
Statistics
Str 20, Dex 20, Con 16, Int 11, Wis 22, Cha 14
Base Atk +15; CMB +23 (+27 grapple); CMD 45 (49 vs. grapple and trip)
Feats Cleave, Deflect Arrows, Dodge, Great Fortitude, Greater Grapple, Improved Grapple, Iron Will, Lunge, Mobility, Power Attack, Spring Attack, Snatch Arrows
Skills Acrobatics +25 (+33 when jumping), Bluff +9, Climb +10, Diplomacy +4, Disguise +3, Intimidate +10, Knowledge (religion) +4, Perception +18, Sense Motive +10, Stealth +20, Survival +12; Racial Modifiers +4 Bluff, +4 Stealth
Languages Abyssal, Common
SQ evasion, purity of body (immune to disease), slow fall (40'), undersized weapons
Environment temperate deserts
Organization solitary
Treasure double, so 32,700 (weapons 12000, protection 9000, magic 8000, limited use 2,700, gear 1000) Monk's Robes (13,000) bracers of armor +3 (9000) cloak of resistance +3 (9000) 200' of silk rope (40)
Special Abilities
Undersized Weapons (Ex) Although a lamia is Large, its upper torso is the same size as that of a Medium humanoid. As a result, lamias wield weapons as if they were one size category smaller than their actual size (Medium for most lamias).
Wisdom Drain (Su) A lamia drains 1d4 points of Wisdom each time it hits with its melee touch attack. (Unlike with other kinds of ability drain attacks, a lamia does not heal any damage when it uses its Wisdom drain.) Lamias try to use this power early in an encounter to make foes more susceptible to charm monster and suggestion.
Ecology: The hate-filled inheritors of an ancient curse, lamias appear as lean and attractive women from the waist up, while below they possess the bodies of powerful lions. Even their humanoid features bear distinctly feline traits, their eyes slitted and feral and their teeth like predatory fangs. A typical lamia stands over 6 feet tall, measures more than 8 feet long, and weighs upward of 650 pounds.
Lamias are attracted to the ruined and forsaken parts of the world. Crumbling keeps, abandoned cities, and forgotten monuments all satisfy these deadly hunters' cruel aesthetic—particularly those in arid or otherwise lifeless environs. Foremost, though, lamias favor decrepit temples. They delight in seeing the shrines of good deities in ruins and go out of their way to bring hardship to thriving holy places.
Lamias look to the eldest female of the group as their leader, mother, and shaman, cleaving to her with fanatical reverence. While lamias shun most religious followings—viewing such as the source of the curse that blighted them with bestial forms—lamia elders claim to hear the whispers of the scouring desert winds and know the cold whims of the stars, drawing upon such mystical sources to lead their people.
Natalia: Natalia is a lion bodied lamia like most of her lesser brethren. She has longed to end the ancient curse that her people suffer under. In an ancient temple she believes the answer has been discovered. Poring over found parchments hundreds of years old she has learned the Way of the Ruined Hand. It is a fighting style attributed to a demon goddess who had the upper body of a six armed woman atop a winged lions lower form. This treatise details methods of offering this forgotten deity sacrifice to end any affliction.
The affliction she seeks to end is the bestial forms of her people. In the ruins of a lost city she has practiced both her fighting arts and her sacrificial understandings. Natalia has already offered nearly 100 lost travelers to her demon goddess and plans to offer 100 more if necessary. She is absolute in her convictions and utterly convinced that her allegiance will bear fruit. If she is not stopped she will continue to haunt the desert and her hidden home until blood soaks the sands red.
Tactics: Her driving need is to gain newer and stronger victims for sacrifice. Natalia begins by observing a group from a distance. She closes in using stealth to great effect (half her movement is 40, so she can move around most campsites quickly and unobserved). She tries to determine who the clerics are because they are the ones she wishes to sacrifice. Next she locates the arcane casters. Finally she attacks by spring attacking up to the nearest combat type (fighter or rogue) and stunning them. She finishes her movement near a caster of some sort. On the next round she attempts to grapple them and so long as she can pin she'll hog tie the victim and carry them off. Being a quadruped means she can carry nearly 800 lbs before bearing a heavy load. If possible, and if she hasn't taken too much damage by this point, she will try to grab another target using the same method as before. If a foe is within reach (this makes lunge handy) she unleashes a full power flurry on them in the hopes of driving off the enemy. Once she has a pair of victims she flees with them at her full 80 movement.
If someone on her back breaks their bonds she uses a full attack on them as soon as she can in an attempt to subdue them. If Natalia is not stopped in time, then anyone she's captured will be sacrificed by the next midnight hour.
Natalia's home is a series of old stone mounds 40' high with crisscrossing tunnels at various levels. Against flying foes she brings all 650lbs to bear by grappling them in mid-air (if possible) and dragging the unfortunate flier to the ground by grappling them while still in the air.
When facing a party that is ready for her she brings the fight to them. Instead of stunning foes she'll sicken her enemy (which last a minute and gives a critical -2 to everything). So long as she can pull it off (can acrobatics even if carrying a hog tied sacrifice) Natalia keeps using hit and run tactics on the party until at least one member is captured.
When wading into combat directly with a large group she activates mirror image first, then spends ki points on her dodge bonus making her almost impossible to hit. With her ability to fatigue instead of stun Natalia can end a barbarians rage or slow down a fast or fleeing foe.
She wields a length of rope at all times (flavor purposes only, no game bonus) which she uses to tie up any potential sacrifices.
With her massive jump check Natalia is capable of jumping 50 to 70 feet at one time and ignore 40 of falling so long as she is near a wall.
This allows her to attack from above with almost frightening consistency.
Natalia has been doing this for a long time. If she cannot capture a party member for sacrifice then she is not above giving up on them in favor of easier prey. Should she be confronted in her temple she will fight to kill, but not to the death. She can hound a party for long periods of time and will not relent if her temple is desecrated. Natalia is a long term enemy that can act as a temporary obstacle to a different adventure or a long term villain should the party require entering her temple.
Here is a quicklink to the grapple rules.