Twilight raced up the stairs of Canterlot Castle. Twelve Royal Guards stormed down the steps towards her, halberds drawn and ready to strike at her. Their eyes were snake-like slits and their bodies bulging with cursed energies, as they bared their fangs with wicked grins. She grit her teeth and powered her magic. A heartbeat later all twelve stallions were stopped dead in their tracks, their bodies surrounded by a purple aura that emanated from Twilights horn.

"Now!", she yelled.

"Way ahead of ya!" Applejack rushed past her and kicked the first two guards in the abdomen. Their eyes bulged out in pain and they were flung against a nearby wall, cracking the marble. Then she grabbed a third one by the face, her muscles tensing as she lifted him up with one arm. "Conspirin' with a demon, huh? Got balls, Ah give ya that.", she growled, as the corrupted guard flailed in her grip, his skull cracking audibly.

Twilight flinched, as her spell was violently interrupted. One of the enemies had pulled out an anti-magic talisman and dispelled her telekinesis-field. "Watch out!", she yelled, as five guards rushed forward, ready to impale Applejack.

Lightning crackled and hit the one at the front, frying him on the spot. Then the two behind him were slammed onto the ground by a cyan-coloured pegasus crashing on top of them. Rainbow Dash grinned at the rest, pulling her thundercloud out and punching two more lightning bolts out of it. Two smoking, twitching guards collapsed onto the stairs.

"Ah had them.", complained Applejack.

Dash just laughed in response. "And I was faster than you."

"Perish, you pesky thots!", yelled one of the guards and pulled out a wand. A burning fireball began to form at its end and he raised his hand to hurl them at the three mares.

"My, my...watch your language, you brute.", said a silky voice. Sheets of blue fabric wrapped around the guards arm and twisted it downwards. The fireball went off, exploding in his face and destroying half the staircase. When the dust settled, Twilight could see that the remaining enemies had been constricted by their own clothing. She looked over her shoulder and saw Rarity strut up the stairs.

"Thanks. How is the battle outside?", she asked.

The fashionista smiled. "Pinkie has taken out their artillery.", she mentioned, which was underscored by the entire building shaking and massive confetti mushroom-clouds blanketing the courtyard outside. "Though, I must say...giving her access to the powder-store might have been a mistake."

"We don't have much of a choice. As long as she and Fluttershy can keep the mind-controlled guards busy, we should be fine.", said Twilight and swiped some sweat off her brow. She felt bad about forcing someone as passive as Fluttershy into battle, but she was the only one who could have persuaded the castle's menagerie into battle. And having a manticore, three rockodiles, two chimera's and even the labyrinths golem fight on their side was crucial to holding the courtyard.

"You alright?", asked Applejack, looking worried at her. Twilight smiled and waved off. "Don't worry about me. I have plenty of power left.", she lied. If she was honest, she was running on fumes. Never would have she imagined that Canterlot Castles defences could so easily be turned against them. She had spent the last hours dimantling and dispelling all the various traps and curses barring their way and the constant battles didn't help. But she couldn't stop now. Not when they were so close....

Applejack clearly didn't buy it, but thankfully didn't press the issue any further. Instead, she grabbed one of the halberds and walked up the stairs with Dash, while Rarity brought up the rear. There were one of three teams, that had tried to storm the castle. Now, they were the only ones left. The strongest fighters left in the capital.

"This is all my fault...", mumbled Twilight.

"No, its not.", said Rarity firmly. "Nopony could have anticipated this."

"It was an outbreak from Tartarus! I should have investigated more closely. I got careless, when we had managed to deal with the prison riot so quickly. I didn't expect it to be just a diversion." She looked around the ruined tapestries, the broken windows and the burning city below. "To think, that one demon alone could cause all of this...."

"We're gonna get that Scortatus-jerk, Twilight! Once we join Celestia, it doesn't matter how strong he is. He is gonna be toast!", boasted Dash, with a confident grin.

Twilight hoped she was right. When they had started the siege on the castle, the throneroom had been visibly set ablaze by violent spells and shaken by Celestia and the demon fighting. But now it was silent for more than an hour. Nopony had come in or out and the castle had been crawling with corrupted guards. Twilight did not have a good feeling about this...

Finally, they reached the throne-room. The massive gates were closed, but Applejack, simply grabbed the handles and pulled them. She was straining visibly, as the crooked, broken mechanism was fighting her. Finally it gave way and the gate swung open.

They were confronted with a shocking sight. Luna lied beaten on the ground, together with half her night-guard. Her clothes ripped to pieces and her curvy body covered in cuts and bruises. Her guards had not been so lucky and Twilight averted her gaze from the gory sight. The entire throne-room was a mess. Pillars laid broken on the floor. Murals were shattered and here and there the stones had partially melted by intensely powerful fire-spells. The stained windows had been destroyed and the tapestry burned to ashes.

But even that wasn't what made Twilights heart stop in terror.

Kneeling before the throne was Celestia, her robe torn and burned, revealing her voluptuous body. Her marble-white skin marred by bruises. Her horn twisted into a wicked spiral. Feathers replaced by wide batlike wings. Kind, motherly eyes turned cruel and lusty, with slitted pupils. And a long, forked tongue flipping out and coiling around a thick, long, veiny cock.

"No....", whispered Twilight, as she stared at her corrupted mentor.

"I would rather say yes, my dear.", answered a male voice. An oily bariton, with an almost youthful bent to it. Like a cocky, young stallion. "After all, Celestia has become so much more pleasant, now that she has joined my side."

On the throne sat the demon. He was tall, easily as big as Celestia herself. His skin a deep, dark magenta and his mane pitch-black. Perfect, chiseled muscles pressing against skin, without bulging. Powerful, athletic, attractive. An eight-pack, on which one could grin meat, and a massive 30-inch long, monstrously thick cock, with cantaloupe-sized balls as well. It was a perverse, debauched body. A perfection that seemed to mock the mere concept of innocence.

"You...what did you do to her!?", yelled Rainbow Dash angrily.

Scortatus shrugged. "I beat her. Took a while, I admit. But they all bend the knee, eventually."

Dash growled in anger and wanted to rush forward. "No!", yelled Twilight, grabbing her by the shoulder. "We have to do this together. As a team!", she reminded her hotheaded friend.

The demon applauded. "Indeed! That is a pretty good idea, when going up against somepony stronger.", he said. Then he grinned. "Although, I must say I'm the worst possible match-up against you, my dear Twilight."

"And why is that?", asked Twilight. She wanted to keep him talking. Buy time to recover some magic and think of something. A plan, an idea. What did she know about demons? They were powerful, ancient. Sealed in deepest reaches of Tartarus. There had been thirteen, when the world had been created. Thirteen traitors to Faust's cause, who sought to corrupt her work, and who had been banished by her, before she departed the world. They were creatures of evil....and laws....

She had an idea. Twilight glared up to the demon and her horn began to glow. "Alright, girls. I have a plan. Keep him busy while I--"

Further she didn't make it, as suddenly her clothes coiled around her body, restricting her arms and choking her. Then she was kicked in the knees and toppled to the ground. "Wha--" Twilight couldn't believe it. Rarity and Applejack stood before her, grinning wide. Their eyes slitted pupils, with black scelera. Rarity's horn sharp and curved and Applejack tail now whipping around hairless, with a barbed tip.

"Didn't I tell you? I'm a bad match-up, dear.", laughed Scortatus. "You probably would have had a better chance fighting me, without such weak-willed allies. Their souls are so easily twisted."

"Twist this, asshole!", screamed Rainbow Dash and unleashed her stormcloud. Thundering lightning crackles through the throne-room and blasted Applejack, Rarity and Celestia off their feet. Dash grabbed the black cloud and aimed it at the demon. Then, with a scream she unloaded into him, blasting him with shot after shot after shot.

Several seconds passed...

Then the pegasus choked, as deep-purple magic caught her and lifted her up. Her arms and legs pulled to the side, she stared in horror, as the dust settled. Scortatus did not even have a scratch! The demon lazily flicked a few specks off his shoulder, his curved horn glowing with magic. He grinned and looked up to Dash. "Not bad. A decent effort. Especially, considering you withstood my natural influence. I guess, the Element of Loyalty is not a title for show."

He raised his hand towards her. "Let's see how far it takes you."

Twilight stared in horror, as dark, corruptive energies poured from the demon and floated over to her friend, forcing their way into her mouth, nose and ears. Dash screams were muffled quickly and she twitched and spasmed, as her entire body was flooded with demonic magic. Her screams soon turned into moans and within a heartbeat into mad laughter. Feather fells out and her wings stretched out to wicked, draconic proportions. Then her eyes turned black and her struggle stopped.

Scortatus released his grip and the newly corrupted Rainbow Dash floated back to the ground. She licked her lips, with her long, forked tongue, and stroked her own body lewdly. The demon clicked his tongue in disappointment, as his newest slave walked over to his side. "Hmm...not far, it seems. I was hoping for a challenge.", he mused.

"A-A challenge?", stammered Twilight, still kneeling on the ground. She couldn't move, her legs refused to. The sheer power against her had overwhelmed her and her mind was running circles. How could they beat this thing? How could anypony beat it?

"Indeed. Languishing in Tartarus since the dawn of time can get quite boring, you see? I heard good things about Equestria and the Elements of Harmony. After all, you managed to defeat Sombra and Tirek. Especially the latter piqued my interest, given that he used some form of demonic magic himself. I figured, might as well break out and see if you can entertain me."

He shrugged and grinned. "Turns out, I miscalculated. Even somepony like Celestia cannot really match up to a True Demon like me. Oh, she tried, but unfortunately....well, I'm too strong." He looked at Twilight and grinned. "Watch this!"

He snapped his fingers and Celestia groaned, as her tits grew from her normal H-Cup to ridiculous sizes. She panted, as she doubled over and her boobs hit the floor, with the corrupted alicorn resting on top of them like pillows. Then Scortatus snapped his fingers again and the battle outside stopped immediately. Pinkie and Fluttershy were teleported to his side and before the two mares could even speak, he snapped his fingers again and they instantly were corrupted into demons themselves. No struggle, no resistance. Just...instant loss.

It wasn't fair....

"Welp...so much for that." Scortatus sighed and scratched his cheek. "But no worries. I think, I can have some fun with this place for the next five centuries, at the very least. I'm not picky, you see. As long as I have enough sluts and bimbos worshipping my cock or debasing myself for my amusement, I can keep going for a looong time."

"Y-You monster...", snapped Twilight, tears running down her face.

"Gee...haven't heard that one today. But no worries, Twilight. You will sing a different tune very quickly~", chirped the demon and raised his fingers.

"Wait...WAIT!"

To her surprise, he stopped. "What? Are you going to beg for your life? I mean, I don't mind. I like heroines licking my feet, while quaking in fear. Its a fetish of mine.", joked Scortatus and winked at her.

But Twilight had no intention on begging. No, she had realized something. An idea, that had popped in her head. A desperate, last-minute gamble. "If its entertainment you crave...then why not make a bet with me?", she asked, slowly getting up to her feet.

"Ohooo? And why would I do that?"

"Because you're bored. You said as much.", explained Twilight, glaring at him and desperately not trying to panic. "You could twist this entire country to your whim, true. But why do that? It would take the fun out of it. You wouldn't even prove anything. Just that you're stronger...."

"Hmm..." Scortatus rubbed his chin, slightly intrigued. "So, you assume that as a demon, I care about proving something?"

"You have to. It was the entire reason for your rebellion in the first place, wasn't it? That a world of peace and harmony was impossible."

"Wrong. Not impossible...but boooring.", corrected her the demon. "Faust certainly knew how to make things pretty, but nothing is complete without conflict. I simply wanted to provide that conflict. To show her, that no matter how harmonious she makes her little mortals, in the end they will all stab each other in the back. Betray, lie and deceive, in order to satisfy their desires."

He stopped, realizing he had leaned over towards Twilight, as he ranted. He coughed, embarrassed and settle back onto the throne. "Well, something of the sorts...at least. It was a long time ago."

"Indeed. And you have not proven anything of the sorts. My friends haven't joined your side out of their free will. You brainwashed them. As you brainwashed everypony! How can you say, that we're all scheming, perverted jerks, if none of us did so out of our free will!", argued Twilight, now standing right in front of him.

She was scared, but slowly but surely she found her footing. She couldn't beat this monster. But maybe she could talk him into making a mistake. He was clearly affected by what she was saying. Her heart beat like a zebra-drum and for a moment, she was afraid he could hear it.

"Hm...what are you trying to say?", he asked. Then he leaned forward again and grabbed her chin, with a smirk. "Oh, and I know you're manipulating me. But I'm intrigued, so...go on."

Twilight held his gaze, summoning as much confidence as she still had. "You release my friends and Celestia and everypony you brainwashed. In turn...I will agree to become your slave. If you break me, without using magic, you win. If I hold out for an entire year, you go back to Tartarus and never return."

Silence followed and Scortatus stared at her. Then he shook his head. "No deal. I will not agree to that."

"But..." He held up a finger, before Twilight could despair. "I have a counter-offer. I'm going to reverse the corruption I spread, as you suggested. But I have no intention on giving up all my new toys, in exchance for just one. No offense, but you're not that important, Twily."

"Buut...I'm not going to mind-control, brainwash or otherwise use my magic to meddle with someponies mind, while I rule over Equestria. Rebellions will be squashed, of course, so don't expect me to voluntarily disarm myself. Your precious Celestia and Luna will stay with me, as guarantees of everyponies good behaviour. Oh, and as my concubines, obviously."

"Are you going to revert their corruption?", asked Twilight, not daring to look at the mocking parodies that he turned her friends into.

"Yes, yes. That too.", said Scortatus with a dismissive wave. "But now we get to the fun part. I will turn you into a demon. Just the basics, really. I will also tie your corruption to a council of likeminded beings and demons, who have preferred to stay in Tartarus when I broke out, but who will no doubt enjoy the show that I will give them."

"They will be with you every second of your life now. Talking to you, tempting you, changing you. Every now and then, they will get to vote what will change on you. Maybe bigger boobs? Or some memories corrupted and smuttified? So, make sure you don't make them angry, or they might punish you later~"

Twilight gulped. That sounded bad. Not just because of her privacy, but becoming a demon? A small part of her wanted to say no, but she couldn't leave her friends in the grip of this demon. If it meant sullying her own soul, so be it. That was a sacrifice she was willing to make, for the sake of Equestria.

"And what are the win-conditions?", she asked.

"Simple...if, after a full year, you come to me and beg me to stay, I win and will plunge this entire country into utter debauchery. But, if you still remain sane enough to refuse me...then I will pack my things and return to Tartarus. As a bonus, I will swear to never break out again."

"How can I trust your word?"

He grinned, his sharp fangs blinking white. "I'm a demon, Twilight. I never lie. I corrupt, I twist, I break...but when I promise something, I will hold to it." Then she shrugged and leaned back. "Besides...not like you have choice, right?"

He was right. Right now, he had all the power and if he wished so, he could kill Twilight. Or worse, corrupt and brainwash her. She had no choice in this. At the very least, they would be getting another shot at beating this monster. One year....one year, she had bargained for everypony. That would have to be enough.

She took a deep breath and looked him in the eye. "Very well. I agree to this bet."

Scortatus grinned wide and laughed. "Good, good! I'm beginning to like you, Twilight Sparkle. I, Scortatus also agree to this bet and I will bind my sould to it!" His last words thundered through the room, echoing down the hallway. The demon clapped his hands and pointed at Twilight. Then he snapped his fingers.

Searing heat drove into Twilights body. She panted in pain and feel to her knees, as she felt her body and soul touched by impossibly vast and unendingly perverse energies. Her head felt like it was split open and every fiber in her body was on fire. She felt her wings retract into her back and vanish and her horn twist into a curved, sharp angle. Her pupils turn to slits, but she fought the corruption back, reversing the change.

Bit by bit, she wrestled with the curse, before it finally died down. Settling deep into her belly, like a clump of coal. Still there, but dormant. Twilight herself was panting hard, sweat dripping from her face. She was no longer an alicorn, her wings gone and her power rotted away. Any arcane and divine energy she had possessed was stripped away, with only the clump of demonic power in her left.

She was no longer a pony. She was now a demon.

Scortatus clapped, impressed. "Not bad. I planned to do more, but you actually resisted the transformation...partially." He chuckled. "Rare to see that. I certainly do not regret this bet now. You will make for some Grade-A entertainment."

"Just...you wait....", panted Twilight, struggling to her feet. "Me and my friends will defeat you and---AARRRGH!!" A searing headache hammered her brain and she collapsed onto the ground. Voices, dozens and dozens of voices. All talking at the same time, in different languages, non-sensical, evil, perverted, mad. It was pandemonium and it all happened inside her brain.

"Ah, looks like connection is not quite stable. Don't worry, it will die down in time.", she heard the demon say, faintly in the background.

The pain now increased and she was writhing on the floor, screaming her lungs out. She didn't hear Scartotus next words. She didn't see him reversing the transformation on her friends. She did not even notice him teleporting her back into her room in her castle in Ponyville. She only heard the voices. Before she went unconscious, one could be heard over them all.

"The Game has begun..."

Author's Note

Hello and welcome,

I'm doujinch and this is my first clopfic. And an interactive one, to boot! I was reading nohen's My Little Corruption a few months ago and it inspired me to write something similar. Now, I hope you will like the premise and will enjoy the story. This first chapter is basically just set-up and we will get into the sexy, juicy bits once the story begins for real.

Now, how does this interactive clopfic work? Well, as Scortatus explained, he will have Twilights transformation into a demon tied to several evil villains and demons in Tartarus. Aka...the readers! You can comment, suggest and talk to Twilight in the comments and every chapter, several of these comments will be incorporated into the story. Twilight will react, argue and even be outright influenced by your comments.

But the real meat comes with the votes. At regular intervalls, the readers will get to vote on how Twilights corruption progresses. This will then be applied and will influence how the story progresses. Will you turn Twilight into braindead bimbo? Or a lusty succubus? Maybe you will slowly twist her, until she turns into a slut. Or maybe, you will help her against Scortatus and ensure Equestria continues to be a happy, harmonious and prude paradise.

Roleplaying is encouraged, though please try to not overdo it or spam. Well-written comments are more likely to be picked for the next chapter. Quality, not quantity.

I hope, you will have fun reading and interacting with this clopfic. I plan to provide heartbreak, action and plenty of juicy, steamy smut for all!