Infernal illness: Type of Demon??

Hi All,

I"m working on a story involving jealousy and sickness, and would love your thoughts on the type of demon that might be at the root of it. (Or is it a dark fae?)

The origin: A strong-willed young princess from Granada is wed to the young, spoiled Emir of Palma. When she catches him continuing to use the royal family harem, she turns to one of her sorceror advisors for aid. He is a fundamentalist, and not very keen on sexual transgressions, and decides to summon a demon to eliminate the temptation: He "infects" the harem with a type of incubus that leaves behind a wasting disease in the victim it rides, which will wither all the beauty of the young women. The problem is that the demon he summons is more powerful than he thought, and the disease spreads, first to other brothels, and then to the general population.

For gameplay purposes, I'm thinking that the characters catch wind of this strange disease, track it to it's source (or "patient zero") and then fight or banish the demon. The goal of the story is to get the characters to meet the new royal family, perhaps this sorceror as well, and get them involved in some of the politics of town.

I'm trying to classify this demon (is it an Incubus, or something else), or figure out if it's a dark fae.
Prostitutes throughout the city become sick, gaining long-term fatigue from the demon. But as the disease spreads to the general population, the new fundamentalist Almohads in town are going to try to clamp down, which causes large unrest. Different political and social factions in the city are going to try to solve the situation, while the characters get to the root of the problem.
I envision the Demon has some sort of "lair," and sends out small, separate coagulations of itself to the different brothels in order to infect them. The women at first are inflamed with a feverish lust. The demon feeds on this, and each male visitor's climax makes the demonlings stronger. (does this sound like vitality to you?) But as the disease continues it's progress, the women wither and become useless to the demon, and the demonling jumps to another victim, probably traveling with the male to his next conquest. This is how the disease demonlings spread to the general population.

The reason to have the Demon have a lair is so that the characters can confront it with magic, without breaking the code. I'm not convinced yet that this is a good enough reason for the demon to be stationary.

I know what the effect is, but I'm trying to figure out what the demon's goal is. If I can classify this demon it might help me define it's goals more. Thoughts?
Does the sorceror still have it bound, and the demon is trying to break free? If so, does this story work within the general Ars Magica rules of warding etc.? Could the demonlings get out of the ward, while the demon itself is bound? Can this be explained away with strange Muslim spirit magic...?

As stated before, the demon is the maguffin... the real point of the story is to get the characters embroiled in local politics, making allies and enemies and contacts along the way. EX. The princess, the head of the fundamentalist guards, the local priest, a crime boss who's seeing his profits dwindle as the fundamentalists enact martial law. So I see the battle with the demon to involve the sorceror somehow, which leads to a future magical contact. Perhaps the sorceror is captured by the demon, and the characters have to rescue him. Perhaps the sorceror is being tortured in a room of lust, but manages to get the characters to retrieve his book of True Names, so that he can send the demon back. Or perhaps the sorceror is sitting in his tower, calmly, watching all the impure souls wither away, and finds it divine justice. The characters have to convince him to act, or steal his book. (Hmnmm... is this demon actually an avenging angel?)

I know I've thrown a bunch of information out here. I invite any and all thoughts. Thanks!

A fundamentalist of what religion? The Emir of Palma certainly has a right to four wives and as many slave girls as he can get his hands on, if he's a Muslim - this is not a sexual transgression. Likewise, clamping down on prostitutes who are spreading disease is not an act of fundamentalist religion, it's just "by the Prophet's beard, we have an epidemic on our hands! We need a quarantine pronto! Oh, Allah, I do not want to have to deal with this..."

Instead, let me suggest that the Princess might be paying the sorcerer simply to eliminate her rivals' beauty and ensure her own place in her husband's bed (more chances to produce the heir, greater influence on the Emir's decisions), not punish her husband for his lechery. Then it's harem politics.

Okay, hold up here. First, slaying a demon is not outside the Code by any means. Second, what would be Code-questionable is that your players have gotten involved in the politics of Palma in the first place - particularly if it turns out to be politics between rival wives of the Emir.

It should definitely be a demon, though. Not an incubus - that's a specific type of tempter. It's a demon of disease spreading something like syphilis. No need for it to be stationary.

(How does the disease get out of the harem and into the prostitutes of the city? Is one of the Emir's wives/slaves seeing someone on the side? How is the princess of Granada protecting herself, and will that protection be a clue as to her involvement?)