HOLY SHIT!! 40k READS?! AGHHFDGXHXHXHX—
But seriously guys, thank you so much for this! It means a lot that you guys continue to read this and vote on it! ^^
And I'm sorry that I've been so slow with updates! I've just been really busy with other stuff and I haven't had much time to work on these.
   But honestly, you should stop expecting request chapters at this point lmao. Not that I won't do requests on occasion (I'm still working on a few requests, but I tend to work more on the stuff that I'm really inspired to do), but honestly, most of this is personal writing.
   But this idea actually came from something my brother brought up during an irl roleplay! Sure, the original concept he started was one of those dumb "stop hitting yourself" kinda things, but hey! It inspired a oneshot!
   Just a bit of a heads up, there will be a fair amount of cursing in this oneshot, some mental manipulation, and quite a bit of physical torture. Not that any of those things bother a lot of you guys (why would you be here if you didn't like those things?) lol
   Oh! And before you point out the flaw in the way Error acts at the beginning, let me explain my writing.
   Error is a madman. We've known this since he was introduced to the fandom. This is why I made him a bit more touchy (?) with Ink, since I can imagine him trying to trick someone into thinking they're safe, then hurting them when they let their guard down. Don't come at me with "He has haphephobia! He wouldn't do that! That's out of character, Sora!"
   No. I headcanon that Error just doesn't like being touched by others. He's totally fine when he comes into contact with someone on his own terms.
   Anyway! Enough rambling! Let's get on with the oneshot! >:3
   (Oh, and the artwork above was drawn by me. ^^)
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   "Łøøk at høw pathetic ÿøu are..." Error snickered, kneeling down next to his beaten down rival.
   The corner of Ink's mouth twitched, his grimace contorting into a snarl. "Y-You aren't winning..."
   Error laughed, tugging a handful of strings from his eyes. "1 beg tø differ, mÿ friend."
Before the artist could do anything, Error's strings wrapped themselves around his limbs, immobilizing him. Using his free hand, the glitch gently lifted his rival's head to look up at him.
The snarl on Ink's face widened, and his eyes narrowed. "Y-You can't do shit to m-me..."
"Aww...Ÿøu wish ÿøu cøułd bełieve that~" Error sneered, just as several more strings launched towards Ink, shooting through his shirt and embedding themselves deep within his empty ribcage.
The artist's eyelights turned to colorless, white rings, and his body seemed to go limp. Error's twisted grin widened, knowing that he now had nearly full control over his enemy.
The glitch chuckled, standing up and commanding his new puppet to do the same. "Can't dø anÿthing nøw, can ÿøu, 1nk~?"
The other skeleton's eyelid twitched, his expression weak and tired. "Y-You're ch-cheating..."
"1s it reallÿ cheating if 1'm just using my resøurces?" Error replied smugly, idly rubbing his chin with his thumb and his index finger. "Nøw... What shøułd 1 dø with ÿøu...?"
   Ink merely grunted in response, much too tired and beaten up to say much else. Error studied the artist for a moment, his temporary frown curling back into a crazed grin as he got an idea.
   "1 can make ÿøu dø whatever 1 want..."
   "Wh-Wha...?" Ink looked up drearily, a slight trickle of black ink dripping from his mouth. "Wh-Where are you g-going with this...?"
   Error chuckled. "Just rełax, 1nkÿ... Ÿøu wøn't get anøther øppørtunitÿ før a whiłe..."
   Ink flinched, a slight hint of color returning to his eyes. "H-Huh...?" He tensed slightly as Error walked behind him, quietly putting his hands on his forearms.
   Strangely enough, the glitch leaned into his rival, almost as though he were trying to comfort him. Ink glanced back with a faint spark of confusion in his eyes as Error slowly pulled his arms up and back towards him, his grip sliding to the artist's hands.
   "Wh-What are you...?" Ink barely had time to react as the glitch suddenly jerked his left arm backwards, contorting it in a direction it wasn't meant to go in.
   He screamed in agony, frantically throwing his head back against Error's chest in a futile attempt to force him to let go. His elbow popped out of its proper place, and he fought the urge to puke at both the sound and feeling of the injury.
   He struggled feebly, pitifully trying to escape his enemy's grasp.
   "Nø nø, 1nkÿ. Ÿøu can't get awaÿ just ÿet. This has ønłÿ just begun!" the glitch burst out into a fit of maniacal laughter, pulling even more on Ink's already twisted arm and tightening his grip on the other one.
   Ink barely bit back another scream as pain seared through his arm, the sound of his bones creaking making him nauseous. "S-Stop... P-Please..."
   "Begging før mercÿ nøw, are yøu~? C'møn, høw pathetic can ÿøu get?!"
   The artist groaned, trying to wrench his uninjured arm out from his enemy's grasp as tears rolled down his cheeks. Error kept pulling back on Ink's forearm, slowly cracking the bone.
   "Wh-Why are you... Why are you d-doing this...?" The creative Sans asked, his voice strained.
   "Ÿøu'łł see~" Error taunted, a sly look on his face as he bent Ink's fingers back as well, popping the other skeleton's knuckles in the same way he'd done with his arm.
   The sharp pain from his dislocated limb quickly gave way to a distinct burning sensation, traveling all the way up to his shoulder and slowly working its way through the rest of his body.
   Deep within his empty ribcage, a darker, hidden energy began to rise up, as if to defend himself from the outside source of his agony.
   At first, his exhausted mind didn't catch on to what was happening. But it didn't take long for him to figure it out from there.
   "Y-You..." Ink shakily turned his head to look back at his rival, a faint hue of red becoming visible at the edge of his eyelights. "Y-You're gonna f-force this...? R-Right now?"
   "0h gøød! 1 was afraid ÿøu wøułdn't be abłe tø cøme tø the reałizatiøn!" Error smirked, his eyes gleaming deviously.
   Ink opened his mouth to reply, but the only sound that came out was a grunt as pain shot through him once more. Error's grin widened as he heard the cry. "What's the matter, 1nkÿ? Can't deał with a bit øf pain?"
   The artist inhaled sharply, ignoring the muffled sound of his bones creaking as he mentally tried to force back the changes. He could do it... He just had to fight back the influence of his enemy's control...
   Slowly, he felt the pressure on his form lessening, and he was able to relax slightly. Sweat rolled down his skull as he strained to keep the transformation at bay.
   Error took notice of this and quickly regained the control he had lost. Ink's body visibly tensed as the glitch jerked both of his arms back, at the same moment that another jolt of pain surged through his chest. He gritted his teeth, trying to stifle another scream, initially succeeding in doing so, but ultimately failing.
   "Ÿøu reałłÿ thøught ÿøu cøułd get awaÿ that easiłÿ?"
   Ink gasped for breath between frustrated sobs and pained cries, struggling weakly against Error's grip and the strings that controlled him as he felt his vertebrae beginning to pop and shift out of alignment, rearranging itself at an agonizingly slow pace.
   "Whÿ are ÿøu even trÿing tø fight it? Ÿøu knøw it can't be støpped ønce it has begun," Error lectured, narrowing his eyes at his disobedient puppet, finally releasing him from the "hug" (if it could even be called that).
Ink's only response was a grunt as he suddenly collapsed to the ground, his body wracked with another spasm of pain. The fabric of his clothing bulged, his bones jutting against the stretched-out material and threatening to tear it.
"0h cøme øn.  Ÿøu're just making this take łønger," Error growled, tapping his foot impatiently as he glared down at the artist.
Suddenly, Ink let out a strained wail as a row of massive spikes ripped through his shirt, running all the way down the length of his spine. It was only a matter of seconds before several more spikes burst out from across his shoulder blades, as well as from his elbow joints.
Ink dragged himself towards the glitch, clutching at the dark skeleton's stitched-up shorts as he struggled to get back on his feet. "S-Stop... P-Please... I-I can't..." he moaned weakly, shutting out the chilling sounds of his bones cracking once more as he fought to stay aware.
   Error chuckled, a smile creeping back across his face. "Ÿ'knøw, ałł this begging just makes me want tø tørture ÿøu even møre~"
   Ink shuddered, inhaling sharply between his clenched teeth. A strong sense of anger began to boil up within him as he glared up at his enemy. "Y-You're fucking s-sick..." His grip tightened, and he barely managed to stifle another grunt as pain surged through him once more.
   "1nkÿ. We've ałreadÿ estabłished that 1'm never in mÿ right mind. Tełł me sømething 1 don't knøw!"
   The artist curled in on himself with a groan, digging his fingertips into the fabric of Error's shorts. The glitch scoffed, flicking the strings that controlled his rival backward and throwing him off. "Enøugh øf that. 1 døn't want ÿøu ripping mÿ cløthes."
   Ink managed to stay upright for only a few seconds before he toppled to the ground once more, catching himself just before he hit his skull. Rainbow-colored magic began to trickle from his eye sockets as he struggled to catch his breath.
   He slowly managed to get himself under control, the transformation coming to a halt. He shivered under the pressure of the powerful magic energy that he was fighting so hard to keep inside, his bones rattling slightly as a result.
   He winced with each breath he took, the repeated movement sending small shockwaves of pain through his ribs. "G-Get it... t-together..."
   Error frowned, recognizing that Ink was beginning to recover some sort of mental stability. "Hm. 1 see that ÿøu've regained a bit øf cøntrøł." He grinned, flicking his strings back and pulling his rival towards him, suspending him in midair so that they were face to face. "And that simpłÿ wøn't dø~!"
   Ink's eyelights tracked the glitch's actions wearily as his hand rose to the side of the artist's face, his thumb stroking his ink-stained cheekbone, which was sharper and more angular than it had been a few moments ago. "Ÿøu knøw, this wøułdn't take sø damn łøng if ÿøu'd just give up ałready..."
   Ink grunted softly in response, his expression appearing weaker than ever. But yet... that determined gleam in his eyes remained, completely untouched by the pain of defeat. "W-Well... Y-You and I b-both know that I'm n-not one who g-gives up easily..."
   "Funnÿ høw ÿøu saÿ that łike it's a gøød thing in this situatiøn. Ałł that stupid perseverance is døing før ÿøu right nøw is making ÿøu suffer møre."
   Ink opened his mouth to respond, but the only sound that came out was a chillingly high-pitched scream as the upper half of his body contorted backwards, his ribs beginning to push against the fabric of his shirt, stretching and tearing it even more than before.
   Error's sadistic smile widened as the tone of Ink's voice grew more guttural and animalistic mid-cry, just as three large spikes shot through the front of his shirt, right where his sternum was. At the same moment, his collarbone suddenly snapped, its broken shards slowly fusing with his ribs and disappearing altogether.
   The artist was beginning to choke on his own staggered breaths, completely overcome by a crippling mental panic. His eyes were stretched wide, his eyelights filling the entirety of the sockets as he wailed in unspeakable anguish.
   Error couldn't help but chuckle as his enemy quickly began to lose his grasp on the careful control he'd kept on the beast within himself. "Remind me again whø ÿøu thøught was gøing tø win this fight?"
   Ink collapsed to the ground one final time as the glitch loosened his grip on his strings, a gut-wrenching moan of agony escaping him. His entire body convulsed violently as his bones began to rearrange themselves at a more rapid pace, the air filled with sickening snaps and pops and accompanied by the horrific shrieking that the creative skeleton had no hope of silencing.
His legs began to restructure themselves, his feet elongating and the tips of his toes growing into cruel, curved talons during the process. He cried out in helpless agony, his voice breaking as his body was wracked by a sudden spasm of excruciating pain.
"Face it. Ÿøu were never gøing tø win this fight. The beast inside ÿøu is tøø pøwerfuł, and ÿøur mind is much tøø weak tø keep it cøntained."
Ink's only response was a strained moan, which was unnaturally deep and raspy in tone. A tail had slithered out behind him, writhing about as he continued to thrash weakly in his agony. As the new appendage grew longer, spikes began to form along the sides of the vertebrae towards the end of his tail, a detail that Error had never seemed to notice during previous transformations.
"1f ÿøu cøułdn't beat me, høw cøułd ÿøu have anÿ høpe øf defeating sømething that łives within ÿøur øwn cønsciøusness?"
The sound that tore from the artist's throat was a chilling mix between a weak groan and a beastly growl as his skull began to change, his features slowly warping as a boxy muzzle pushed outward from his face and a number of curved horns emerged from the back of his cranium.
"1t's pøintłess tø keep fighting it. Ÿøu're tøø far gøne tø førce it back nøw." Error's expression turned serious. "Give. 1t. Up."
The artist's body began to shift and expand, growing exponentially larger in size as the minutes ticked by. His bones grew longer and thicker, and the gnarly spikes that had developed on his form grew sharper as he began to resemble his regular self less and less.
Error's twisted grin widened at the sight of his old enemy's horribly mutated form, a chill of adrenaline crawling up his spine. "That's møre łike it..."
The beast whined pitifully, remaining where he was on the ground. The glitch frowned, disappointed by his rival's reluctance to fight back. "0h cøme øn. What fun is there in słeeping when there's a battłe tø be føught!"
Error flicked the strings controlling the massive creature upwards, forcing him to stand up. The beast gave another weak growl as he staggered about on unsteady legs, too disoriented to force his oversized body to move.
   "Funny... Ÿøu wøułd think after ałł that struggłe..." The glitch narrowed his eyes. "1 wøułd expect ÿøu'd be itching før a fight..."
   The creature huffed, shaking his mutated skull from side to side, refusing to look his enemy in the eye. Error, clearly irritated, summoned a dark, pixelated blaster and aimed it at Ink.
   "Ałright... Maybe this wiłł trigger thøse fight ør fłight refłexes..."
   He commanded the glitched skull to fire, the blast hitting Ink in the side of the ribs. The beast was knocked off-balance a bit, causing him to roar furiously.
   When he had regained his balance, his attention became fully focused on Error, his eyelights changing to upside down pentagrams.
   The glitch smiled, tugging another handful of strings from his eye as the ones controlling Ink became inactive. "Cøme øn then. Fight me łike the mønster ÿøu've ałwaÿs been."
   The creature crept forward, rainbow smoke pouring from his maw as his tail lashed back and forth behind him. His dagger-like talons clicked against the floor as he made his advance, his gaze never leaving his rival.
   Error's smile widened as he heard a soft whine, alerting him that his enemy was charging up a blast attack. "Gø ahead. Kiłł me. Ÿøu've døne it enøugh times beføre. What's støpping ÿøu nøw?
   A ball of swirling rainbow energy began to build up in Ink's parted maw, the low whine gradually becoming louder as the energy continued to build.
   Just as the beast fired the blast, Error darted out of the way with a loud, crazed bout of cackling, commanding his strings to grab onto the creature's foreleg and pull him off balance a bit.
   This was it.
   The final battle had finally begun.

   I guess you can consider this both a 40k read and 500 follower special lmao
   But... I do have some unfortunate news regarding this book...
   I do not think I will be continuing these, at least for a bit of time.
   I have kinda moved away from Undertale a bit in recent times, and I've been lacking a lot of motivation to finish these. That isn't to say that I won't come back to these, but just... Not right now.
   HOWEVER! If you enjoy the angsty transformations, or my writing in general, I'd suggest you check out my new oneshot book, "Cryptid Identity V AU Oneshots"!
   Identity V is an AMAZING game you can get on your phone (if you want to check it out), and I ended up making an AU of it with a bunch of discord friends.
   My new oneshot book consists of transformations and general angst, but also touches a bit on fluff that I haven't been able to play with a whole lot.
   To spark interest... Here are some of the AU designs for the characters (this is slightly older art tho, so beware lmao)! :D

Lucky Guy is a werewolf (who turned from a very unusual cause... >:3)

The gardener, Emma Woods (left), is a plant monster, and the priestess, Fiona Gilman (right), is a demon

Fiona's concept was made by EmeraldUmbreon and her design was made by me

The mechanic, Tracy Reznik (left), is a cyborg, and the doctor, Emily Dyer (right) is a werebear

The embalmer, Aesop Carl (left), and the "prisoner", Lucca Balsa (right) are both vampires (and they're very gay for each other lmao)

Aesop's design and concept was created by EmeraldUmbreon, and Lucca's was created by me

The lawyer, Freddy Riley, is a werebunny (and is also everyone's favorite snack lmao)

The postman, Victor Grantz, has a hellhound named Wick

The cowboy, Kevin Alonso, is a werewolf (though he constantly denies it)

The coordinator, Martha Behamfil, gained the ability to turn into a dragon after getting caught up in one of the enchantress's spells (Her design and concept was created by EmeraldUmbreon)

And the mercenary, Naib Subedar, is a wendigo

There are a lot more characters in the AU, but they haven't been designed.

   Anyway! Hopefully y'all will check that out, regardless of being in the fandom or not. I'm really happy with how those oneshots turned out, especially since transformations with human characters give me a lot more to work with than the skeletons I'm used to.
   Yes, they are humans, but that doesn't mean that their transformations aren't angsty! (Even if they aren't always painful, there's still a lot of weirdness to the whole thing that makes it fun to write and read lol)
   Like I said, I might come back to these eventually, but right now I'm having a lot of fun with Identity V. You guys understand that... right?
   Either way! Hopefully I'll see some of you in my Identity V oneshot book! And if not, thanks for sticking around for this long! I love you all! Take care of yourselves! 💙💚
   - Sora 🐾