corruption

by a touch of sparkles

Rating: everyone
Tags: My Little Pony: Friendship is Magic, Dark, Spike, Twilight Sparkle
Length: 4743

twilight gets corrupted

After the beginning of season 3, Twilights interests have been focused on dark magic after it was introduced to her. She keeps this a secret due to the general beliefs around dark magic. Its all going well until it starts to affect her physically. Surely that headache will go away...right?

This does take place in a AU, however the main focus of the AU is not present in this story
Cover art is by me

Published 2021-08-13 15:30:00 UTC
Last updated 2021-08-16 12:40:32 UTC

just a simple headache

The crackling of dark magic filled the room as it bubbled around Twilights horn. She had to admit that stealing spell books out of Sombra’s study wasn’t one of her best ideas, Celestia forbid he came back and found his room raided. It certainly didn’t help she had taken his diary, but being it written in a different language she simply said she was going to take it (and a few other books) home to translate it. But the introduction of dark magic had picked Twilights curiosity.

She was hiding these new practices from everyone, she always took her chance to practice when Spike was out on his own. She also had to be careful as she doubted a hollowed out oak tree could withstand run away dark magic.

Over the past weeks she had managed to translate the language that Sombra seemed to speak, although she hadn’t read his diary yet. She felt it was a boundary she wasn’t yet ready to break. The dark spells in the other books were written in equestrian, however the spells didn’t seem to work. She had translated them over to the other language, but she was stumped as she had no clue how to pronounce it.

“my head” Twilight groaned as she rubbed her forehead with her hoof. The sun was setting but she doubted she would sleep with such a headache. She packed away the books neatly into a trunk and lifted it back up to the top shelf. She drags her hooves as she heads to bed, Spike had returned without her realising. Fortunately it appears he just collapsed on his bed without noticing her secret. Twilight saw her bed and she too collapsed on top it.

Twilight awoke the next day to two things. The smell of pancakes and an even worse headache. It felt like her horn had inverted itself and went straight into her brain. The smell of the pancakes is what dragged her out of her bed. She made her way down the stairs, she could see Spike in the small kitchen that was cramped into a unused corner of the Golden Oak Library.

“Morning Twilight” Spike said rather merrily.

“Good morning Spike” her usually cheery voice was replaced with a groggy groan. Spike turned to look at her, noticing the change.

“You alright? You look like you haven’t slept, like at all” Spike asked with concern. Twilights ears were folded back, her headache worsened as she used her magic to lift up a plate.

“Headache. I should be fine in a couple hours” Twilight sat at the table as she munched on the pancakes Spike had so kindly made for her. He sat down and began to eat his, with a healthy topping of gemstones.

“they’re not as good as pinkies” he said to himself, comparing his work to their friends.

“Nopony can make sweet treats as good as her Spike” Twilight replied to him. They didn’t talk much after that, Spike knew not to talk to her when she had a headache.

Twilight made her way back up to her room. Spike had left again, apparently he was helping out Applejack with the cider making.

“if there’s one thing I could do with it’s a nice glass of cider right now” Twilight told no one as she sat back down at her desk. She looked up at the trunk. She knew that her headache was definitely due to the dark magic, the only other time before now had hurt her head. So it was safe to say that prolonged use had led to her situation.

“I’ll just sleep it out. That’s usually a good idea” it seemed like a good idea when she flopped back into the comfort of her bedsheets, but only rest came not sleep. Apart from the headache, the trunk was drawing her attention again.

“maybe a little bit won’t hurt” she said as she pulled herself back off the bed, she sat back down at her desk and pulled out some of the spell books.

“Perhaps I should just try levitation. That’s as simple it can get after all” she ignited her horn and slowly it shifted from a magenta aura to a black one. The magic seemed loosely in her control. She tried to pick up her quill. The dark magic swirled around it as it shook violently before lifting up from the desk. A strong stab of pain shot through her head, promptly making her drop the quill.

She took a deep breath. Then she ignited her horn again and picked up the quill. Slowly she made progress. She lifted a cup of pencils, then a stack of paper. Eventually she was lifting up the books and reading from them as they floated.

Twilight looked over some of the other spells in the books. There was a few she recognised that she had seen Sombra use. One being the fear inducing spell, studied from some animal called a tormentor. Apparently the ability to turn to shadow was more of a biological spell, like a pegasus being able to sit on clouds. It was only known to be performed by a pony like creature called Umbrums.

The spell about the shadow had a picture of this umbrum creature. They were unicorns with curved horns, they seemed freakishly tall if the size comparison of a typical pony was correct. Apparently they weren’t classed as ponies due to multiple of things. The large sharp teeth and back claws were one thing. But it was the omnivorous diet and the dark magic that were the big contenders to it. She continued to read about the creatures.

“They live in the north as tribes…usually in groups of ten to twenty…unable to use light magic, that’s interesting…become lactose intolerant as they age…can’t have chocolate or coffee, that’s sad…oo this is seems interesting…it appears that they have been corrupted by dark magic, this is presumed as it’s the most readily available magic in the north. It seems to have changed them in a way that makes them well adapted to the harsh climate of the north…maybe I can find some and oh wait, last sighting was over a thousand years ago” the mild disappointment didn’t stop twilight from her reading, which was distracting from the pounding headache.

Twilight hadn’t noticed the time go by. That was until she heard the door to her bedroom open and for Spike to see her, surrounded by floating books engulfed in dark magic.

“Uh Twilight-“

“HI SPIKE!” Twilight launched the books back into the trunk and shoved it back on the shelf. She was already caught though, she smiled awkwardly at him.

“Were you just using-“

“Yep”

“You think that’s why you have a head-“

“Most likely” there was a brief silence between the two of them. Spike broke it first.

“Why?” Twilight knew she had to tell him, after all there was no hiding it now from him.

“I’ll admit I got interested after the ordeal with Sombra and the empire. I took some books from his study. Promise you won’t tell anypony” Twilight didn’t want her secret to get out. He didn’t tend to blab too much, however there is always a chance it could slip by. She felt like if others found out about her practising dark magic she would be seen as some form of evil. After all the words dark magic don’t make many ponies think good things.

“You promise right” she asked for extra confirmation.

“I promise” Spike confirmed for her. She gave a sigh of relief, but then the headache came back to her attention. She rubbed a hoof on her forehead.

“You still have that headache?” Spike asked noticing the pained look on her face.

“I’m sure it will be gone tomorrow. I’m just going to head to bed” Twilight could swear the pounding in her head had gotten stronger ever since she had lifted all of those objects. She pulled the blankets over her again, hoping that by the morning this headache would be gone.

But things are never that simple.

not a concerning fever

Twilight felt like she had been bucked twenty times in the head the next morning. Her legs were like lead weights and she was shiny with sweat, yet at the same she shivered violently. Another groan left her mouth as every movement was exhausting. That groan woke up spike.

“You ok Twilight?” he asked her, his voice still croaky and unsteady from sleep. Spike rubbed his eyes as he looked over at her and became even more concerned when he saw her cringing face. He crawled out of his bed and pulled himself onto hers. He placed the back of her hand on her forehead, something he had learned from her. He never thought he would have to use it though.

“You really warm. How are you feeling?”

“Bad”

“That’s not very useful. What like symptoms do you have?”

“Headache still, my legs feel dead, I’m sweating yet I feel cold” Twilight shoved her head into her pillow, her ears curled. Spike rubbed his chin a little then left the room. Twilight felt the need to call him back for comfort, but she didn’t have the energy. Spike returned five minutes later with a glass of water. He placed it on her bedside table.

“I read one of your books and it seems you have a fever. It also said that you might be dehydrated so I bought you a glass of water”

“Thanks Spike” Twilight gave him the biggest smile she could muster, even if it was at most the hint of a smile. She lifted her head to take a drink, she didn’t dare use her magic. She used her shaking hooves to lift the glass to her lips and took a short drink. It didn’t settle right, but it seemed to stay in her stomach which is good enough for her.

Twilight laid her head down on her pillow. While she wishes she could rest the pounding headache simply wouldn’t let up. She was unable to find a position that would let her muscles rest, her hind legs were particularly stressed and just wouldn’t relax.

“Anything else you need?” Spike asked her, wanting to make sure she was as comfortable as possible.

“books”

“Knew it” Spike wandered of out of the room again to get some of her books. While she was waiting her stomach became unsettled. Then the familiar sick feeling came to her. On instinct she rushed out of her bedroom to the bathroom. Where nothing but bile dribbled out of her mouth. Twilight collapsed at the base of the toilet. Her head began to pound again as the world spun.

Slowly she lifted herself up, the bathroom floor wasn’t comfortable, and neither was the chill. She looked at herself in the mirror. Her eyes were dull along with her fur. Her hair was greasy from the sweat that had dripped through it. What startled her was her horn, it was slightly bent backward.

“Twilight?” Spike was standing confused in the doorway, multiple books were stacked in his arms.

“Is my horn bent or is it me?” Twilight looked fearfully at Spike. Her mind flashed back to those umbrum creatures in that book. Spike cocked his head to look at her, his scally brows furrowed as he stared at her horn.

“Not really…” Twilight knew he was lying to try and comfort her. She side eyed her face in the mirror. There was definitely a bend there. A wave of nausea wafted over her, Twilights knees wobbled beneath her. Twilight took it as a sight she should go back to bed, she followed spike back to her room. She looked over the books he had picked up. Most of them were Daring Do. Twilight didn’t mind though, she could immerse herself and ignore the still constant throbbing in her head.

Twilight pulled herself back under the covers. Her stomach had been relieved and she felt slightly better. Spike handed her the first book. She propped the book up on her bedside table. But Spike asked her a question before she started to read.

“Why were you in the bathroom?”

“I threw up. I think my stomach got upset” Twilight rubbed her head as if it would relieve her headache.

“Have we got any pain relief. My head still hurts” Twilight asked, Spike almost ran down to the kitchen to get her some. Twilight often forgot just how much he would care for her, although she was sure he had picked it up from her from when he became ill. She rested her head down on the pillow. The letters in the book seemed jumbled.

A few pills were placed on the bedside table. Twilight lifted them in her magic and placed them in her mouth, she hadn’t realised she had used magic, she hadn’t realised it had turned black. But the pain in her head had covered it. She swallowed the pills and started to slowly read the book. Spike had sat down in his usual spot and started to right a letter. When he sent it the bright light aggravated her eyes.

“I sent a letter to Celestia. So she knows why you won’t be writing for a bit” Spike said as he picked up his comics. They both read in silence for some time. The pain relief slowly started to kick in, although the pain was still very present. She groaned and rubbed her head as the words became jumbled again.

“Spike. Where are you going?” Twilight had noticed Spike leaving the room. Although he didn’t answer, but he was wearing a face that suggested he had an idea. Twilight sunk her heavy head deeper into the pillow. Her eyes closed as she attempted to sleep. But it was interrupted within an hour, when a cluster of hooves could be heard coming up the wooden stairs.

“HEY TWILIGHT” Pinkie’s voice leapt through the doorway, followed by her body. A sandwich box was strapped to her back, through its clouded plastic Twilight could see some cookies. Rainbow floated through the doorway, although she seemed slightly quieter than usual.

“Hey pinkie, you know ill ponies don’t like loud noises right” Rainbow said to the pink pony.

“Oh right…I made cookies though. Fresh from the oven!” while pinkie was still loud, she wasn’t shouting and Twilight quite appreciated it. The other three stood behind them, each having their own concerned face.

“I though you might like some more company” Spike said as he held is arms out, displaying her friends to her.

“We came as soon as Spike told us” Fluttershy said quietly, she had trotted over and placed a wing over Twilight. Then it was Applejack turn to speak as she sat down next to her.

“Ah hope you’re alright sugar cube. Not feeling too bad are ya?”

“Apart from the headache and the muscle ache…I’m not the worst” she did sugar coat it a little bit, as not to make them worry too much. Pinkie opened her box of cookies, the fresh smell of cookies made its self-known in her nose. Her appetite suddenly came back to her. Pinkie started to give out the cookies to her friends. Twilight slowly took bites out of hers, Twilight had always loved pinkies chocolate chip cookies. She just hoped her stomach wouldn’t mind.

“So when did you start feeling ill?” Fluttershy asked her.

“Yesterday. I think the headache turned to a fever overnight” Twilight told her as she continued to eat her cookie. She could feel her stomach turning. However she held back her needs to head to the bathroom. She didn’t want to insult pinkie. Twilight noticed Rarity seemed to be staring at her

“Twilight dear. I don’t mean to sound rude but is your horn bent?” Rarity gave her a concerned look. Being a unicorn, Rarity could easily spot problems with a horn. Curved horns only ever happen if they are damaged during growth or there’s a genetic problem. They certainly aren’t a normal appearance, being quite tough its hard to damage them without extreme force.

“I think so. I don’t know why…” Twilight stared upwards trying to see her horn.

“I’m going to bet that horns bending is not a normal fever symptom” Rainbow said from atop the ceiling rafters. Her wings draped lazily down her sides.

“I didn’t see it in the book on common illness, and you have thrown up already. The book said if vomiting is persistent to get medical help. I think I might go get a doctor” Spike said with concern as he processed the seemingly strange symptoms.

“I’ll be fine spike. Fevers usually pass after a few days.” Twilight told him as she shifted her body, each muscle complained in unison. Another wave of nausea came over her, she tried her best not to vomit.

“Are you sure?”

“I’m sure spike” Twilight tried to convince him she was fine, but the wince of pain from her didn’t quite convince him. However the subject quickly changed when Pinkie started to talk.

The group continued to exchange recent stories. Pinkie lamented over a horrible order, Rarity talked about the distinct lack of gemstones in the caves, or at least the ones she needed. Fluttershy talked abut her animals, and Applejack and Rainbow dash talked about the day before when they raced around the orchard. Then it was Twilights turn. However Fluttershy seemed to have caught on about Twilights recent absence from the outside world. And of course Spike already knew.

“I haven’t been doing much…mostly just practicing magic and…reading and stuff” Twilight awkwardly said as she tried to form a half lie. Spike could see right through it, some of her friends became suspicious. However they didn’t push it. Fluttershy looked up through the window carved out of the tree’s trunk.

“It’s getting dark. We should leave Twilight here to rest” she said as she removed her wing from over Twilight. She headed towards the door with a soft smile. The others followed her as they said their goodbyes, then they left the library and headed back to there own homes.

Once she heard the door close she bolted out of bed, despite her muscle’s protests, and vomited into the toilet again for the second time that day. It burnt this time on the way up, stomach acid was forced up with the digested cookie. Now just a vile mush with some pinkish liquid mixed in. She felt spikes hands grip around her leg. But then he said something that horrified Twilight.

“Twilight. Your cutie mark is disappearing”

everything starts to change

Twilight stood in shock as she stared at her flank. Spike was right it was disappearing. The pink star was cracked down the middle and it had become pale, almost being the pale purple of her fur. the white stars surrounding it had almost completely faded and were barely visible. It scared her. There had never been a case of cutie marks spontaneously disappearing.

“Do you think this has something to do with the dark magic?” Spike questioned, Twilight realised he may be correct. It all lined up to well that she, someone who rarely got sick, would become ill after practicing dark magic. Her line of thought was interrupted when her headache hit her at full force again.

“Spike have we got any more pain relief?”

“I think you had the last two, I’ll go check though” Spike ran off from the bathroom, Twilight made her way back to the bedroom. She prayed they had more. She did not want to endure a headache like this for much longer. She collapsed on the bed and pulled the pillow around her face.

why is my cutie mark disappearing? Is my talent going to go to? When will this damn headache go away?

“Twilight…we don’t have…anymore. I’ll go to the hospital to pick up some more ok?” Spike said, his voice full of sympathy. Twilight’s response was a muffled and mumbled version of “alright”. Before spike left her alone, he gave her leg a squeeze.

Twilight was left alone in the library again. Her head was ripping itself apart and her nose felt incredibly tight. The skin around it had become so sensitive the soft pillow was irritating. Her muscles protested as she turned onto her back. She lifted the book from her bedside table above her face in her magic, which was dark without her even trying. The book plummeted and dropped on her face as a stab of pain rushed through her, losing control of her magic. The book hit the hardest on her nose, but her teeth also caught some of it. She licked them with her tongue.

Her teeth felt weird. Almost thinner instead of the wide squares they usually are. She rubbed her tongue around the rest of her mouth. The gap between her incisors and molars suddenly felt quite lumpy. There were little sharp points underneath the gums. As her tongue dragged down her gums she could feel a split. Twilight gasped slightly and felt it widen. But as her gums opened they seared with pain and she yelled.

Twilight leaned herself over to look at her face in the mirror. Her mouth had torn but at the same time it seemed neat. The blood that was slightly starting to appear wasn’t its usual crimson, but a pure white. Almost silvery and shiny. Twilight stared at her new face, it didn’t look like her yet it did. Her nose had lengthened and the bridge became less angular and was smoothing out.

Her horn had bent some more. It was getting darker at the top, the same colour as her eyes. It had become more segmented and the back of each segment, to Twilight’s horror, had a single spike stretching out of it. It made her horn serrated down the back like a bread knife.

Twilight stared over at the trunk of books. She ignited her magic but forced her own out of her horn. She was focusing on keeping her magic stable so hard she was struggling to undo the lock on the trunk. Slowly she opened it and lifted the book from yesterday over to her. Her magic wobbled between light and dark, between magenta and black. She opened the page to those umbrum creatures. She just felt like her face looked like them.

The picture of the stallion was before her again. Twilight realised that her new face appeared similar to his, just more feminine. They both had longer snouts and their horns were both curved and serrated. Twilight started to read over other things about them.

“It seems dark magic might be the reason they have silver blood…there manes and tails float like a alicorns, however it appears their-ow stupid head- it appears that their mane is part shadow…adults have claws on their hindlegs whereas the foals have hooves, there is a lack of evidence, however it is believed this change must happen through puberty.”

“Am I turning into…an umbrum. No it can’t be it must be something else…but it just seems like it is” Twilight shut the book and placed it to the side. Deep in her mind she knew she was being changed by dark magic, she knew it was partly her fault.

She heard the door open downstairs. Then the quick footsteps that she could easily identify as Spikes. The searing pain returned in her head as she slumped back down into her pillow. Spike appeared in the doorway with a smile.

“I got some” he said merrily as he placed them on the bedside table, he picked up the now empty glass and went downstairs to refill it. After a couple minutes Twilight took some more pills with the cold water he had bought her. Spike then stared at her new face, a look of horror spread across his.

“Twilight…” his voice shook. Twilight reopened the book and turned it to the correct page and gave it to spike.

“It said they were corrupted by dark magic. I think…I think I might be turning into one” Spikes eyes were still wide as he picked up some parchment and a quill.

“Spike. Please don’t tell Celestia she’s the last po-“

“You don’t have a choice Twilight. She’s going to notice eventually so you may as well tell her now” Spike told her as he began to scribble on the note.

“Please Spike-“

“No Twilight. You have to tell her. Besides, if your corrupted by dark magic then what if your element won’t work?” Spike raised a good point and it’s what made Twilight let him right the letter and send it. He was right. Celestia would find out eventually and so would everyone else.

Twilight watched as the letter turned to smoke and flew out the window. The light hurt her eyes, the pain relief hadn’t kicked in yet and sitting up to watch it was a bad idea. Her head became woozy as she flopped back down. Her hindlegs were hurting more than she realized. They ached and complained as she moved them. A letter appeared in a blaze of gold before spike.

“She said she’s busy but she’ll be here as soon as she can” Spike told her. Twilight nodded as she rubbed her forehead.

“I’m going to get something to eat, do you want anything?” Spike asked as he got up to leave the room again.

“Something small” Spike nodded as he left and went down to the kitchen. After he left Twilight groaned as her hindlegs started to complain even more. A deep aching pain was in them. Her bones creaked and grinded against each other. Her eyes screwed shut as a single movement triggered a flood of pain.

She pulled her legs out from under the covers, they seemed normal but her hooves appeared crooked. The cloven split extended further up then what it normally did, it was at this point Twilight was happy that she couldn’t feel her hooves.

A small plate of salad was placed next to her. Twilight smiled weakly at Spike as he sat on the bed next to her. He started to eat his bowl of gems, although rather slowly. Twilight could tell he was upset.

“Are you alright Spike. You’re eating quite slow” Twilight asked him softly.

“I’m worried for you Twilight. What if Celestia doesn’t know what to do and what if your element doesn’t work anymore. What if- “

“I’m sure she will know what to do Spike. Let’s just relax and wait for her to get here. I’m not in the mood for panicking” Twilight said as she began to eat her salad. She ate it straight of the plate, not wanting to play a game with her magic again. Twilight ate slowly as to not upset her stomach. After some time they both finished their small meals.

The sun slowly began to set as Spike took the plates away. Twilight picked up another book he had bought her yesterday. Slowly she began to read while the pain relief finally started to kick in. yet the pain in her legs simply didn’t go away. fortunately it slipped into the back of her mind when she got engrossed into a good book. Her fever run body eventually fell asleep, the book resting on her head.

Twilight didn’t have a restful sleep however. While she told Spike not to panic she really was doing so. Her fever should have gone by now, but at least the headache could be subdued. Her face had changed so suddenly she still couldn’t process it. let alone the fact she looked rather dog like now, yet there was a strange mix of equine still in there. Her hindlegs had started to hurt and her horn was curved and getting darker. She couldn’t keep her magic straight and her cutie mark was vanishing. Twilight just hoped Celestia could help.

Author's Note

not gonna lie I think this chapter came out quite bad. it took me over three days to write it as i have had writers block. but I still felt the need to put a new chapter up, i might wait a bit for my ability to write comes back to me before I make the next chapter.