You walk through the aisle, and stop once you feel a creepy chill run down your body. Your vision is mysteriously drawn to a dark corner of the shop, far away from everything else, and seemingly empty.
But somehow you knew it wasn't.
You approached the place and found yourself in front of a dense brick wall. Anyone else would've just turned around and left, but you knew something was off, an imperceivable, but annoying vibration within your mind itself was driving you crazy, and it only grew stronger with every passing second.
In a quick fig, you grab a nearby fire extinguisher and hit the wall with it. After a few minutes, you manage to break past the bricks and tear down the section of the wall. Stepping in, the vibration gets way worse, and you stumble upon an eerie pillar, on top of it, you see a sinister skull figurine, made of marble of the deepest black color.
You stare at at the statue, and soon it's eyes lighten up with a bright red light. The vibrations in your mind become unbearable, and in an attempt to stop it, you jump and smack the statuette off the pillar, making it hit the ground and break in many pieces.
Sighing in relief when the vibrations disappear, you notice a red mist leaving the remains of the skull, and when you try to back up, it quickly moves towards you and enters your nose and mouth.
It feels like you've breathed in fire and smoke, and you cough at the sensation.
All of a sudden, you feel a deep rumble in your body. You start to feel a stretching sensation all over, and your limbs start to lengthen.
Growling in discomfort, your figure starts to bulk in all places, you stare in disbelief as your muscles painfully throb and expand, and your arms lengthen more. Your hands bulge and expand, fingers lengthening as you gain huge claws.
Your legs soon follow, as your legs expand and gain large muscle mass, your thighs becoming huge pillars of meat. Your knees bend backwards and you stand on your lengthening toes, giving you a digitigrade posture. Your feet expand and your toes gain sharp claws. With a reflex, you stomp the ground, causing everything around you to shake and your claws to leave a cracks on the ground.
Your body grows more and more, back muscles thickening and bulging, abs becoming defined and swollen, and overall body size expanding well beyond the most extreme capabilities of the human body. Your skin soon takes a sickly grey tone, becoming thick, but also hairless and smooth.
Your pecs expand more, this time filling with supple flesh as you gain huge breasts, each one the size of your head. Your nipples become a deep, dark grey color and thick as thumbs.
You flex all your muscles involuntarily as your genitalia becomes a thick, leathery set of black lips.
Clenching your fists, you feel uncomfortable as a long tail ending in a spike grows between your muscly, still expanding, pumpkin-sized glutes, and your knees and elbows grow vicious, deadly spikes.
Your still human head looks awkward in the huge, muscular and womanly body that goes down your neck, but soon, black veins that run throughout the rest of your body expand to your face, giving it a distinctive grey skin, soon your nose becomes sharp and petite, your cheekbones rise high, your lips thicken into plumpness and gain a black coloring, and your ears expand into long, elf-like ears.
You're astounded by the changes, but then, a fast, strong wind moves all around you, forming a whirl around you, and soon a strong hurricane. Fire forms in it, leaving you in the middle of a giant fire tornado. Everything around you burns into an inferno, but you're not bothered by this. You like and embrace it, and soon come to realize it's your body that's causing it by your presence alone. Your dark veins gain a bright orange hue, becoming something similar to magma.
Your smooth head starts growing massive horns, a huge pair extruding from the sides and expanding upwards, being soon replicated by a smaller upper set, giving you what appears to be a giant, monstrous crown made of your own demonic horns.
Your shoulder blades throb as suddenly a giant pair of bat-like wings make their way out of your skin. Opening the entirety of your wingspan, they glow with an orange, flaming hue.
Your eyes begin to emit a bright, orange light, your mind being consumed by thousands, millions of years of knowledge. You grin with your new perfect teeth as sins corrupt your mind, a life ruling the underworld giving you an extremely confident and perverse personality.
Your breasts soon begin to lactate a glowing orange liquid. Somehow, you know this is evil essence, straight from hell itself, capable of corrupting everything, living or not into whatever perversion you wish.
Your muscles bulge once more, your horns expand, wings lengthen for the last time as you flex and let out a massive, feminine roar. The fire tornado burns the whole shop, the whole town block, the whole town as you let out just a sample of your immense power.
Flying above the debris, you will a massive throne to emerge into existence from the ash-covered wasteland beneath you.
You take a seat on your marble throne, and overlook the apocalypse you've just brought to this land.
You're now an ancient, immortal being. Capable of corrupting everything around you, inspire terror and destruction with your presence alone, and being the key to the doom of this world. A nameless queen of sin, evil itself incarnate.