I do not even know where this came from I swear. It kind of abducted my fingers for several hours until BAM 5K monstrosity sitting in my google docs. It's completely unedited, so read at your own risk.

This fic is part of the Gravity Falls Transcendence AU, curated at .com. This fic will make no sense if you haven't read up on that first, and if you're in the Gravity Falls fandom you should check it out ANYWAY because it's an amazing AU. (Just go the blog's headcanons, art, and fic links and type /chrono after the end of the tag. That way you can read up on it from the beginning.)

Aside from general 'verse details, this fic draws on the following headcanons specifically:

- Alcor gets a cult and Mabel thinks it's hilarious (/post/99329835448)
- Dipper has a 'super saiyan' demon mode (/post/99204436318)
- Dipper will 103% flip his shit and USE that super saiyan mode if you threaten or hurt his friends/family (but especially Mabel) (/post/99204463038)
- There was an incident when Mabel had to sell her soul to Dipper to save her life (/post/99203830813)

Warnings for moderate blood/gore, and mentions of animal cruelty.

"The rabbit blood hasn't been working to summon Alcor."

"Maybe we need something bigger?"

"What if the sigils are wrong? Or the incantation?"

"No way - our source knows what he's doing. He sold us the information after summoning Alcor himself, remember?"

"Maybe we inscribed them wrong."

"Maybe. It's a complex summoning circle - maybe something's amiss."

"We can check it over. If nothing's out of place, though… our next sacrifice should be bigger. Much bigger."

It was a quiet Saturday afternoon in the Mystery Shack. The sun shone through the attic window, illuminating the dust particles swirling through the air. Mabel sat cross-legged on her bed, laptop whirring softly as she scrolled through a news article. Dipper floated in the middle of the sunlit room, eyes closed and reclining in the air as he drifted peacefully through his mindscape.

Until Mabel threw a pillow at him with a shriek of laughter.

Startled into wakefulness at both the sound and the pillow's impact, Dipper lost control of his levitation for a moment and fell halfway through the floor with a yelp. Mabel only laughed harder as he righted himself and floated upwards, arms folded over his chest and an indignant frown on his face.

"Sorry, sorry," she said, hiccuping a little between laughs as she waved off any complaint he was about to make. "Look at this, though! You have a fan club!"

She handed her laptop up to him, still clearly biting back laughter, and Dipper began to read the short article. He glanced up at his sister in confusion after a few lines completely devoid of demonology.

"Mabel, this is a wildlife review. How does this relate to me?"

"Just keep reading," she said, grinning broadly and still exuding good humor. He eyed her skeptically, but turned his attention back to the screen.

Local park rangers have reported a marked increase in the number of small animals killed in the area, many of which are found in a condition that suggests ritual sacrifice. After consulting a supernatural authority regarding the symbol found on or near these animals, their deaths have been attributed to the cult of the demon Alcor.

Dipper almost dropped the laptop.

"Mabel, how exactly is this a good thing? These people have been murdering small animals because of me! And don't call them my fan club," he added darkly, casting a glance in her direction. She shrugged a little and gestured for her laptop back, a grin still lingering around the corners of her mouth.

"At least we know why you've been having power surges every other day," she offered. "If we can get them to stop, maybe you won't randomly get your body back in the middle of a wall anymore."

Dipper grimaced. "If I'm gonna be corporeal, I want it to be on my own terms. That was incredibly annoying."

"That poor wall has never been the same since," Mabel said mock-mournfully, clasping her hands as if in prayer. Dipper chuckled for a moment, before his expression grew sober.

"In all seriousness, though, we really need to get them to stop. We don't know how many there are of them or how dangerous they are, but if they're at the point of regularly killing animals..." He let the sentence trail off. Mabel nodded, their shared experience with the supernatural allowing them to imagine all too clearly the damage that people like these could cause if left unchecked.

After a few moments of silence, Dipper felt the first tugs of a summoning begin to pull at him. He turned to look at Mabel one more time before he left to hear out his summoner.

"I have to go, but see if you can do some research on anything else relating to the cult, okay?"

She stood up and saluted him with a grin. "Aye aye, sir! One heaping plate of fan club information coming right up!"

"Be careful," he warned, then disappeared.

Mabel turned back to her laptop. Stared at the screen for a moment or two.

Then decided to go on a walk.

The research could wait an hour or two, right?

Wrong.

Wrong wrong wrong, she had definitely been wrong, she regretted that walk immensely, and she had learned in the past several minutes of wakefulness that the sticky side of duct tape tasted awful.

She'd barely been outside twenty minutes before her relaxed guard had landed her in trouble. She should have learned by now not to leave the house unprepared - even before the release and spread of the supernatural - and not even twenty minutes had gone by before she'd been ambushed by at least six hooded figures. They'd knocked her out before she could put up a decent fight and brought her to what was apparently their headquarters - a source of both good and bad news.

Good news was, she'd found Dipper's creepy little fan club. The room's chipped plaster walls, illuminated by a fire hazard's worth of candles, were covered in various runes and sigils that Mabel recognized as mostly harmless. The floor, or what she could see of it, was covered in an incredibly intricate summoning circle done in blood-red paint. She recognized the runes for 'Alcor' repeated in an unbroken line around the circumference - at least she doesn't have to worry about dealing with a demon on her own, if their summoning works. Well, Dipper IS a demon, but he's not a demon demon. He's her brother. There's a difference.

Bad news is, she'd found Dipper's creepy little fan club. The ones who seemed to have no problems about killing or mutilating small animals to summon a demon. The ones who currently have her bound hand, foot and mouth with duct tape in the middle of the summoning circle for said demon. The ones who, for all the spooky vibe they managed to give their little hideout, somehow missed a glaringly obvious sigil error. Great. So not only had she been overpowered by members of her brother's cult, she'd been overwhelmed by members of her brother's completely incompetent cult?

Her musings were cut short by the arrival of at least ten or fifteen other cultists, including one with a golden sash across his dark robe. Probably the leader, then. On leader guy's signal, one of the hooded figures walked over towards her spot on the floor. Mabel tensed, ready to headbutt the person into submission if she had to, but relaxed slightly when all they did was begin to peel the tape off her mouth. And a good thing, too, because that adhesive tasted disgusting. Once the tape was removed, Mabel took a deep breath and flexed her jaw before staring up at the leader with as much confidence as she could muster. Given that she was lying on the floor and bound with duct tape, the effect was altogether not as impressive as she'd hoped. The tape was still off though. she'd take what she could get.

"You do realize that those two sigils are backwards, right?" she said, nodding towards the sigils in question.

Her captors looked slightly nonplussed. Probably thinking something like 'oh, aren't captive demon sacrifice collateral people supposed to be weirded out?' Pfftt. Amateurs.

Leader guy stared imperiously down at her. "What would you know about summoning demons, girl?"

"More than you, apparently," Mabel replied. "Seriously. Check it out. That one should be over there, and that one should be over there, and did you people even check your summoning circle before you tried to sacrifice bunnies over it?"

She nodded towards the faulty symbols as she spoke, and shook her head at the cultists. Dipper would probably be offended to know that his cultists were so incompetent, and besides - depending on the type of mistake they'd made, they COULD have summoned a demon she wasn't prepared to handle. One of the cultists bent over to check the symbols she'd indicated before returning to the huddle of their compatriots. They whispered frantically to each other for a few minutes with all the fervor of college students who'd forgotten the order in which they were supposed to give presentations. One of them glared at her, then at the sigils she'd pointed out, then turned back to the group. There was more whispering.

Eventually, someone brought out a small bottle of turpentine and rubbed the incorrect sigils away, painting over the wet spot on the concrete floor with the correct ones. Mabel grinned.

"See? Told you."

The leader leered down at her. "You just solved our problem, little missy. Now you get the great honor of calling our lord Alcor onto the mortal plane."

Mabel's grin faded slightly at the man's words. That... didn't sound good. The last few times they'd dealt with cults, they'd only been using summoning circles and incantations. Knowing that these people had already sacrificed several small animals, she really didn't like where this was going. Should she call Dipper in for this? No, nothing was going too badly right now, and he was out on a contract. She could still handle this. Probably. She could probably still handle this.

As the entire group of cultists descended on her at a signal from the leader guy, she reflected that she probably should revise her estimate of her ability.

Dipper was halfway through the task he'd been summoned for when he felt the tug on the bond he shared with Mabel. It was stronger than any summons he'd ever received, stronger than any call he'd ever felt from her, and a dark edge of worry twisted in his gut. She should have been at home, she should have been doing research - anything that could have happened for her to call for him this strongly was more important than any contract he'd taken. He closed his eyes and opened the bold he shared with Mabel more fully, panic beginning to rise. Something was wrong.

Dipperpleaseyougottacomequickthey'regonnakillmedipperdipperdIPPERHELPME-

The stream of thoughts, full of panic and desperation and fear, fear that his cheerful little sister should never ever have (not under his watch), abruptly cut out into white noise as the link flooded with agony.

At the same time, Dipper felt the tug of another summons.

Oh no.

He followed both the tug of the summons and the desperate call of his sister (who hurt her, who caused her panic, he was going to KILL THEM-) as fast as demonically possible, hurling himself through the mindscape until he exited on the other side. His heart was pounding, breaths coming quicker, and blue fire wreathed his body, instinctually flaring up with response to the panic and fear and anger that anyone would dare to harm what was his. In material time, the journey took a fraction of a second. For Dipper, it felt like years.

A number of tapered candles blew out in the gust of wind accompanying his arrival, but he paid no attention to such a minor detail. Instead, he froze in horror. Three things about the room in which he found himself sent his previously agitated thoughts screaming to a halt, three devastatingly clear and yet completely incomprehensible things, because how could this have happened?

He was surrounded by a circle of robed, hooded figures, hands still raised from the end of the summoning incantation.

The air hung heavy and metallic with the stench of the blood he'd been summoned with.

And Mabel lay crumpled on the ground in front of his feet, at least two liters of blood pooling around her from the gaping rent in her abdomen.

Ignoring the jubilant sounds of the cultists ringing the circle at his arrival, he immediately doused his flames and sank to the ground, gathering Mabel's upper body into his arms. She blinked up at him and smiled weakly, eyes clouded.

"You… came," she said, voice catching on a throat tight with agony. Blood continued to seep through her sweater as he held her.

"'Course I came, you were making such a ruckus," he said, the feeble joke an attempt to mask his raw panic. "We're gonna patch you up, alright? I can fix you, I can still do that, Mabel, stay with me, come on."

Dipper heard the cultists shuffling nervously around him, vision narrowed down to Mabel's shallow breathing and fluttering pulse and the slick feeling of her blood soaking through his gloves. He had to act now, he had to help her, he had to do something before Mabel went somewhere he couldn't follow her. He choked on his breath when her eyes slid closed.

Clutching her slumped form tight against his chest, he blinked them over to the mindscape.

Mabel sat up slowly, recognizing her silver-toned environment as Dipper's dreamscape. Her brother was hovering in the air, a mixture of worry, fear, and guilt writ large across his face.

"Oh thank god you're okay I was worried I was gonna be too late to help you and I mean I slowed time way down in here so we can work this out for as long as we need to but I'm still really sorry about the hole in your stomach but I had to do something about the other hole in your stomach and -" he babbled, before Mabel grabbed his wrist and yanked him down for a hug.

"Shh, Dipper, it's okay. I'm here, right? Not dead yet, still got all of my - oh. I guess that's what you meant when you said 'hole in your stomach', huh," she said, releasing him from the hug and poking at the perfectly round aperture in her abdomen. She vaguely recalled Bill Cipher having done the same thing to Dipper the first time they'd gone up against each other, although she was pretty sure the evil dorito had a lot less noble of intentions than her brother did. Even so, he fidgeted guiltily before pointing to something suspended in midair behind her.

"I figured you wouldn't want to be dealing with that right now, and I'm not really sure how injuries work in here, but I didn't really want to take chances," he explained. She turned around to look at the object he was pointing at. Blinked. Then turned back to face him.

"I've seen some weird stuff, but a cylinder-shaped piece of my abdomen has definitely got to be one of the weirder ones," she said.

"Mabel, be serious about this! Or do you not remember the gaping slash wound you have in your stomach?" Dipper berated, pacing the floor in agitation. "We have to do something, okay?"

"I am being serious! This is my serious face," she replied, watching her brother continue to pace and wondering how long it would be before he realized he was walking on the ceiling. Deciding to show him mercy, she grabbed the collar of his tailcoat and tugged him back onto the floor. He gave her a nod of thanks, scowling at the ceiling for a moment. When he looked back at Mabel, she wore an uncharacteristically serious expression.

"You've healed me before, right?" she asked. "Can't you just do the same thing again? How much would I owe you?"

Dipper sighed heavily, the sound carrying the weight of the world for all its brevity. He looked down at his shoes.

"Mabel, you're… dying," he said, a noticeable hitch in his voice on the last word. "If I hadn't pulled you into the dreamscape when I did, you would be gone."

"So? It's just an injury, right? Can't you fix it like normal?"

"It's... a bit more complicated than that," he said, voice as heavy as his sigh.

"How complicated, exactly?" Mabel asked slowly. Whenever Dipper tried to weasel his way out of giving her a straight answer, it was because he was trying not to tell her something he knew she wouldn't want to hear. What price could patching her up possibly be if he was dancing around the issue this badly?

"Saving someone's life, giving them more years when they should have been cut short… That requires a lot of energy. Which means a higher price."

"Dipper," she said forcefully, glaring at him with all the irritation of an impatient sibling. He would talk around the issue all day if she let him, and near-omnipotent dream demon he might be but they didn't have that kind of time. He looked up from his shoes and met her eyes, clearly startled by the steel in her voice.

"What?" he asked warily.

"How much is it going to cost to save me this time?" she demanded.

A shadow fell over his golden eyes, and he clearly fought the impulse to stare at his shoes again. He closed his eyes and took a breath.

"Your soul. For this contract to work, you would need to sell me your soul in exchange for saving your life."

Dipper's voice was barely more than a whisper. When his statement was met with silence, he looked up at his twin in confusion. She had to have some kind of reaction to that, right? Horror, shock, maybe even revulsion…

Or, apparently, none of the above. Mabel was laughing. Unbridled, body-shaking laughter, like he'd just told her the funniest joke she'd heard in a week. He definitely hadn't been expecting that one.

"Sorry, sorry," she said, valiantly attempting to get herself back under control. "It's just. That's all you were worried about?"

She dissolved into hysterical, full-bodied laughter once again, a somewhat impressive feat since her diaphragm was technically halfway across the room. Dipper hummed angrily at her for a moment before grabbing her shoulders with a sharp glare.

"How is this in any way funny?" he exclaimed, shaking her a little. "Do you not get what that would entail? I would own you. Not just your body. I would own your mind, your heart, I could possess you whenever I wanted, force you to do anything I wanted. You'd be a puppet. And I. Am. A. DEMON. Do you REALLY think it's a good idea to give me that kind of power?"

He stared at her, breathing heavily from his little tirade. Mabel blinked twice, wide-eyed, processing everything he'd told her. Then she sighed, and sank down to the floor.

"Dipper, come down here," she said, patting the floor right beside her. He complied, drifting gracefully down to the concrete and settling into sitting crosslegged. He looked at her expectantly, and she gave him a soft smile.

"Remember what you showed me in the third journal, when you first found it in the woods? That thing the author said about trusting people?" she asked, tugging at one of his hands until he relinquished it to her. She began tracing small, swirling patterns on the back of it, trying to get him to relax. Dipper's shoulders were tensed, still, and she could see the turmoil written on his face clear as day. Her brother had never been one for poker faces.

"Trust no one," he said flatly. "Which is exactly what you should be doing. How many times do I have to-"

"Shhhh," Mabel interrupted, lifting her free hand to place a finger against his lips. "Shh. Just listen. What did you do when you read that warning? Did you decide to not trust me anymore just because the author told you to?"

She removed her finger from his mouth, a clear indication for him to answer her question.

"... no," he answered, voice subdued. "No, I didn't. You're my sister, Mabel, why wouldn't I trust you?"

She smacked him in the back of the head. He flinched back from her, raising a head to the affected area and rubbing it gently.

"What was THAT for? Jeez," he said, shooting her a disgruntled look.

"That," she replied imperiously, "was because you're an idiot. Dipper, I love you, but you can be such a moron sometimes. You still trusted me, even after all the weird supernatural stuff happened, right? You're my brother. I trust you, too - can't you see that? I don't care if you're a demon, I wouldn't care if you were a pack of gnomes -"

He looked at her skeptically. She verbally backspaced.

"Alright, maybe I would care if you were a pack of gnomes. But the point is, there's no one I'd rather trust with my soul than you. No one. I love you, and I trust you," she finished, gently holding his face in her hands as she said her last few sentences. Yeah, he had freaky eyes, and pointy ears and teeth, and his voice always had a weird back-echo on it and sometimes he burst into flame and made it rain frogs when he was angry. But he was still Dipper, still her brother, and there wasn't anything he could do to convince her not to trust him.

He sighed, standing up and offering Mabel a hand as well.

"Are we gonna do this, then?" he asked resignedly, staring at their still-clasped hands.

"Yep!" she replied cheerfully. "Patch me up, little bro!"

"Ugh, don't call me that, he grumbled. Mabel just grinned.

"Anything else I should know about before you start?" she asked, expression serious this time.

"I'll make the contract, but it's gonna knock you out for a while. It's a really serious injury - even with demon-powered healing, it would still be better for you to not move for a day or two," he cautioned.

"Got it," she replied, and squeezed his hand tight enough for him to wince. "If that's it, then let's do this thing!"

Dipper smiled wanly, but ignited the hand she held to finalize the deal.

And everything went dark.

When Dipper released his hold on the dreamscape, Mabel's sweater-clad body was still clasped tightly to his chest. He released her slightly to check her over, in case there was something he'd missed when he'd begun to heal her. Thankfully, everything seemed in order. The gash in her belly was closed over, the once-gaping wound now scabbed over into a thick mat of congealed blood. Not pretty, and Mabel's sweater was officially ruined, but - and here's the most important thing - she was going to be okay. Dipper could have fallen over with relief to see her chest rise and fall in deep, even breaths.

"Lord Alcor, are you… displeased with our sacrifice?" asked a nasal, tentative voice, interrupting his assessment of his sister's well-being. Still holding her upper body in his arms, he looked up at the speaker. He was of medium height, with thinning brown hair and watery eyes. His sash denoted him as the leader of this little cult.

And the reason why Mabel had to sell him her soul in the first place.

The surge of very human emotions running hot and heavy through his veins - residual panic, heavy guilt, and a steadily growing amount of fury - were nothing but kindling to the fire of demonic wrath. Dipper allowed his human-like guise to slip partly away, exposing one eye burning with golden flames and skin the color of the void. More golden fire scorched brightly through the darkness in the brick-like patterns he'd inherited from Bill Cipher, but the sentiment behind his rising fury had nothing in common with the other demon's old tricks. These people had damaged what was his. And they were going to pay for it in every way he knew how.

"You were the one who did this?" he asked. The warped echo that always accompanied his voice grew louder, deeper, and wavering candlelight reflected on bone-white fangs too sharp for any human to have. Some of the more fearful cult members recoiled at the sight of him, and he bared his newly-sharper fangs at them in a twisted mockery of a smile.

"Y-yes, my lord," stuttered the leader. "I thought a larger sacrifice would please you, a-and it has, yes? You arrived because of this one's blood, after all."

He gestured at Mabel's body as if it were a museum exhibit. Dipper snarled, pointed ears pinned back in anger. He'd curved over Mabel's body, he noticed with mild surprise, as an instinctive display of protection. Whether those instincts were human (she's your sister, you're the mature one, you have to take care of her) or demon (she's yours, she's yours, you claimed her as your own, your territory, and these pitiful lumps of flesh and bone dared to touch what's yours and they have to PAY), he didn't know. The golden lines crawled their way across a little more of his body, skin and clothing burning away to black in its wake.

Dipper's ears twitched as one of the cultists behind him rustled for some paper. He whipped his head around to pin the unlucky person with his gaze, golden fire streaming from his eyes and opened mouth as he moved.

"Don't. Move. I'm not done with you yet," he growled. Their hands trembled like leaves, but they froze in place out of terror. Turning his attention back to Mabel, he gently slid one arm beneath her legs and stood up, lifting her as he stood. Dipper carried her a few paces before bending down and laying her with the utmost of care on the floor along the wall. Igniting his hands with blue fire, he concentrated on spreading it out into a protective barrier. He wasn't going to take any chances with his sister. Not after what had just happened.

A web of yellow lines faded in and out across the blue membrane of flame, meeting Dipper's satisfaction. He hadn't been lying before he'd made the contract with her - she did need the sleep. But he knew that if she was awake, she would try to stop him from wreaking his vengeance. And that was something neither his human or demon side could condone.

Making one more pass across the flame barrier, Dipper rose to standing. He stared around at the cultists, some of whom were terrified and some who were just confused. He locked eyes with the leader once again. Rage bubbled up inside him and spread in burning golden lines across his skin, completely consuming the rest of his human appearance. Bat wings spread out behind from his waistcoat, black as the void, and the blue fire balled in his fists grew abruptly brighter.

The last of the candles in the room snuffed completely out as the third fiery eye traced itself across his forehead.

"See, there's a few things you should know about demons," Alcor said, deriving an odd sort of pleasure from the humans' panic as the light snuffed out. They'd all huddled together in the center of the room, as though safety in contact would somehow help them. Ridiculous. He paced in front of the group, polished shoes clicking on the concrete floor.

"One is to never summon a demon out of your league," he continued, holding up one finger tipped in flame before flicking it down towards the summoning circle painted on the floor. "You people are clearly idiots, if you thought this circle could hold me."

It was true. The circle they'd used to summon him was one he'd seen about a month back, done by some guy who wanted out of midlife-crisis debt and had probably Googled basic demon-summoning twenty minutes before drawing the circle. It barely had enough power to call him in the first place, much less bind him. Humans were so arrogant to think they could control him, and so lucky that he was usually nice. Dipper was nice. Alcor was not. He had the feeling that his more human half would regret this later, might even have nightmares over it. But he honestly didn't care. These grease stains called on Alcor. And Alcor they were going to get.

He raised his hands as though conducting an orchestra, separating the members of his little fan club into rank and file before him, and continued to walk between them. He could see them struggling against their invisible bonds, squirming in midair like their paltry mortal strength could ever counteract a demon of his caliber. Really, it was their own fault for thinking they could summon him with impunity after what they'd done. Which brought him to his next little lesson.

"Second is to never mess with a demon's property. Ever. That girl you almost killed? She was mine. And you DARED to touch her, dared to HURT her?" he said, still walking around the suspended cultists. Click. Click. Splish.

Alcor stood there for a moment, standing in the puddle of Mabel's blood, savoring the heavy waves of terror rolling off the captive cultists.

"You did the one and only thing that you POSSIBLY could have done to earn a death sentence. You made me mad. And that brings me to your third lesson for today, class," he grinned, gold fire trailing from his mouth and eyes as he advanced on the humans. "Never make a demon angry with you."

"What are you going to do to us?" one of the cultists asked. Their voice was shaking so bad that Alcor could barely hear them.

"What am I going to do to you?" he replied with a chuckle. "Well, let's see. How about I show you a little test run? Now, who should I break in first."

He walked on the air, silencing his movements and extinguishing his flames as he wove in between the perfectly upright humans on the floor. None of them could see him, none of them could hear him, and he relished the feeling of their panic and terror. Good. They should fear him. Stopping before the front row, he ignited his blue flames once again.

"Hmm, let's see." Alcor paced slowly down the line, tapping each human's forehead for emphasis as he did so.

"Eenie... meenie... miney..."

He stood at the center of the first row of cultists, directly in front of their leader. He stared the man down, golden eyes spilling trails of fire holding watery blue like a snake might captivate a bird. This was the man in charge of the operation. This was the man who had hurt what was his. And this was the man who was going to pay the hardest for what he'd done to her. In an instant, his mock-playful behavior was completely gone. In its place he revealed a creature of dreams and of nightmares, a creature whose voice rang out with the screams of a thousand demons, humans, and monsters alike lost to his strength.

And in that voice, Alcor spoke only one word to the cult's terrified leader.

"YOU."