Noticing how the townspeople stare at you, you look at yourself and see why. Your body has transformed into something inhuman. Your 5'10", thin frame has been completely coated in silky white fur. You panic at the sight and run from the crowd gathering around you, darting down a narrow alley to hide. You hear the noise of the street fade away and crouch behind a pile of crates.
A puddle in front of you catches the light from the small gap between buildings and provides a mirror for you to examine yourself. Your body is still shaped like a human, but that is where the similarities end. Your head and face now look like that of a fox, though you also have small horns that protrude just slightly from your fur. Your eyes glow with an inner fire that shines through amber lenses. Your hands are now paws but you still have opposable thumbs, each finger tipped with retractable, razor-sharp claws. You feel your face with your new hands and there is no denying that both are real.
A cool breeze ruffles fur in places it shouldn't, and you realize that you are completely nude. Your body, though the same size, is much stronger and more toned, making you feel and appear more powerful than most humans without bulging with muscle. A tail flicks behind you, long, slender, and prehensile while your feet have become digitigrade paws. The final change you notice is your male equipment: your balls have grown to the size of large lemons while your member has been hidden within a furry sheath.
You can't stop yourself from touching it gingerly and immediately experience a wave of euphoria. Bracing against the crates, you see something truly frightening as, instead of a normal penis, or even an animal's, what emerges from your crotch is more accurately described as a snake. It is black and scaly, red eyes staring at you and mouth drooling pre-cum. It grows to three feet long and as thick as your arm, facing you and seeming to...smile?
Your cock nuzzles your arm and flexes its jaw, revealing that it has no teeth and spraying you with flecks of your own fluid. You are entirely repulsed by this thing, but somehow also curious. Sure this was crazy, but it had felt amazing and it clearly wanted you to do something. You mentally chastise yourself for taking orders from your own dick, even if it was now sentient. It nudges you again eagerly and you can't stop yourself from petting it.
The pleasure is intense. Though it appears like a normal snake, it is even more sensitive than your human member. Its eyes glaze over in lust as you stroke its length, and you realize it is much more expressive than an ordinary snake. Looking closer, you see that its head is much wider than its neck, like a viper, but the flare is very reminiscent of a circumcised penis. It closes its mouth and eyelids (another difference from a normal snake) and now looks like just a long, black phallus, though the occasional movement of its jaw and its scaled texture ruins the illusion.
Your cock wraps itself around your wrist and guides itself with your hand to your face. You realize what it wants, but you're not sure you can bring yourself to do it. The snake senses your hesitation but won't take no for an answer. It pushes its head against your lips until you have no choice but to give it access. You give in and open your mouth wide, taking a good six inches of it into your muzzle. You moan softly with the wave of pleasure this gives you and salivate at the taste of this thing: salty and slick from your precum. You find your own taste delicious and eagerly suck at it for more, all the while inhaling your own musk which has become intoxicatingly alluring.
You are so drunk on yourself that you don't notice the sound of footsteps coming down the alley towards you. You moan loudly around your new member as the snake spews your demon seed down your throat, hot, creamy, and savory. The footsteps grow louder and you finally take notice, spitting your cock out, which becomes agitated at the interruption and hisses at the intruder: a man wearing chain mail armor and a sword. He has no helmet, revealing his rugged face with thick brown stubble and short-trimmed hair. His chest piece consists of a golden triangle emblem on a red field, point up with a red circle inscribed within.
"You are a very odd demon," he laughs. "Most would be more subtle amongst humans in order to try to corrupt them. You show up in a crowd of people and run away to corrupt yourself."
As if it were a normal thing to do, he grabs your snake's head with lightning fast reflexes. His thumb presses against it oddly, immediately rendering your cock docile, losing its snake form and becoming just a large, black penis. He releases your member which shrinks to a more normal size and retreats into your sheath.
"I think," he jokes, "you're doing it wrong."
You are absolutely lost for words. You have no idea how to describe what has happened to you nor explain this man's reactions. Your stunned silence only makes him snicker more.
"Your pheromones have no effect on me," he explains, "I am protected from corruption by the goddess Irmyne. I have been tasked with protecting this land from demons and monsters of all sorts. But then..." he pauses, realizing something isn't right.
He sees that you do not look at him with hatred or fear, but simply confusion. You aren't looking for a way to escape or overpower him; you are sitting there in the alley listening to him blankly.
"...You're not a demon, are you?"
"No."
"By the gods, what happened to you?" he asks, now offering you his hand and sheathing his dagger. You accept his help and get up from the dirt, brushing your white fur off.
"I have no idea," you answer honestly. "I was walking through a park and came across a path which led me here. You all seemed like ghosts until suddenly everything became solid and I had changed into this. I panicked and ran, and...well, you saw the rest."
"A curious story indeed," he responds, stroking his beard thoughtfully. "By the sounds of it, you have been the victim of some black magic which transported you here and turned you into a demon of lust. Unfortunately I cannot treat dark magic, only fight it. So, unless you want me to kill you, the only help I can offer is to guide you to a white mage to reverse the spell. I know of one who lives in the forest beyond, but I cannot leave this town unprotected; evil has become more prevalent as of late, perhaps a cause or symptom of the spell which you find yourself under. I will house you tonight, and give you enough supplies to make the journey, but you will have to travel there alone."
You thank him for his generosity and follow him down the alley to a small door. He knocks and is greeted by an old man who seems happy to see the knight, but when he sees you his eyes widen in fear. The knight whispers something reassuringly to calm the elder, who nods and goes back inside. In a few moments, he returns with a pile of clothing, which he passes to the knight to hand to you before retreating inside once more, the door slamming behind him.
"You must understand that your spell makes you taboo for those unprotected by divinity or magic to interact with. Fortunately his age inhibits him from falling prey to the effects of your pheromones as easily, but with prolonged exposure even he may have been seduced by your scent. I must ask you to wear these garments; their heavy fabrics will help cover your scent so that you do not corrupt any innocent civilians."
You received from the knight linen drawers and a set of brown woolen hose (reaching your mid-calves and tight at the cuffs) with a codpiece, which took you a minute to figure out how to wear correctly. You then donned a red woolen tunic which reached down to your thighs and was held at your waist by a fibrous belt. The tunic was long-sleeved and hooded, allowing you to partially conceal your appearance. Over this was a short, brown leather vest with loops and pockets for you to carry things.
Your final appearance wasn't too bad, actually, sort of like a red Robin Hood if the archer had also been a demon. You immediately noticed that your scent was highly diminished, and you didn't feel quite so aroused as you had before. Apparently, your pheromones were so strong they affected you, too. But now that they were covered and constrained, you could think much more clearly, the pull of lust gone for the moment.
Once you were properly clothed, you followed the knight to his home: a half-timbered building near the main gate you had entered through. The first floor consisted of a shop you assumed belonged to him selling weapons, armor, and equestrian equipment. He then took you upstairs past the second floor to the attic. A small platform was built across one half of the joists, providing enough space for a single bed and table.
"This will be where you may stay the night," the man instructed, setting a lantern on the table as the sun outside sunk below the rooftops. "Tomorrow I will give you some supplies and you must make your way to the white mage. Rest well and good luck."
"Wait!" you stop him as he begins to descend the stairs. "Thank you for your kindness, but I never got your name."
"I am known as Graven, Killer of Demons," he replies, much more stern than he has been all evening. "Be thankful that you are not truly one...and be wary that you do not become one."
With that, he leaves you in the silence of twilight.