This was requested by Barbacar. It's an alternate scene during Weirdmaggedon. I hope this is what you were looking for! :D
I own nothing, all belongs to Disney and Alex Hirsch
"Looks like it's too late for your friends, Stanford!" Bill turned from the zodiac members he had turned into tapestries, pointing at Dipper and Mabel. A blue pyramid cage rose from the ground trapping the two, both making noises of protest.
"Kids!" Stan yelled out and Ford gasped in horror.
"But you can still save your family!" it closed in locking the two in place. The yellow demon turned to the two older twins, "Last chance, tell me how to take weirdmageddon global and I'll spare the kids."
"No! Don't do it!" Dipper reached through the cage towards his two great uncles.
"Yeah! Bill makes bad deals!" Mabel's voice caused the yellow monstrosity to turn towards the younger set of twins.
"Don't you toy with me Shooting Star!" Bill moved closer to the younger twins. His next words were drawn out and a pitch deeper, "I SEE EVERYTHING!" Mabel made her move while the demon's singular eye showed a purple nebula, she brought out the can of spray paint from within her sweater, she had grabbed it in the commotion from earlier, spraying Bill right in his eye. "Ow! Not again!" the monster cried bringing his hands to hold his eye in agony. "Why? Every time?"
"Nice shot, pumpkin!" Stan managed to get out before he and his brother were released from their glowing restraints, both letting out a surprised yell. Both men groaned when they hit the ground.
Bill had turned from the younger twins still rubbing his eye, "I just regenerated that eye!"
"I know that hurts, because I've accidentally done it to myself, multiple times," Mabel jammed a thumb towards her chest with a determined grin spread across her face, braces reflecting the odd blue light from the cage.
Dipper pulled out the flashlight with the crystal on the end, he had made sure before they left it had been on the enlarging side before they left the Shacktron, he flicked the flashlight on. Blue light emanated from the end making the cage around the younger twins get large enough for them to hop out from between the bars while Bill moaned in pain. "Save yourselves!" the boy's arm pointed away from the monster while his sister jumped up and down trying to get the attention of the dream demon. "Run! We'll take care of Bill!"
"What?! That's a suicide mission!" Ford called out in a panic taking a few steps forward, while Stan could only helplessly stare at the kids with his hand outstretched.
"Trust us," both younger twins stepped towards the older, both their young faces filled with determination. "We've beat him before…"
"And we'll beat him again!" Mabel finished for her brother with a fist bump, both had their weapons of choice in their opposite hands. "Hey, Bill! Come and get us," the kids waved their arms trying to get the monster's attention, "you pointy jerk!" Dipper and Mabel sprinted towards a hallway leading out of the Fearamid's throne room, Bill made a noise of pure rage, his whole body turning red with anger. Mabel stopped a moment to stick her tongue out at him, before turning and sprinting after her brother again.
"What? No! It's too dangerous!" Ford called out to the kids, before he and his brother tried to run after them. They were both stopped dead in their tracks, their hands coming up to their necks, clawing at whatever invisible force was holding them there. They kicked and writhed under the pressure choking them.
"Not so fast! You two wait here!" the cage where the younger twins were once held retracted into the ground before rising up and trapping the older twins. "I've got some children I need to make into corpses!" the monster's body glowed with yellow light transforming into something terrifying. It's now red body with multiple arms, legs and mouths, blinked once at the twins, "See ya real soon." It's nightmarish laugh echoed as it moved after the children, the older twins calling out in a panic as the monstrosity chased the kids.
The monster caught up to the kids in no time, the extra limbs adding to it's speed, the monster's growl could be heard over the children's panting breaths. "When I get my hands on you kids," part of Bill's body took out the wall, "I'm gonna disassemble your molecules!" Dipper grabbed his sister's shoulder and tugged her down a random hallway as the beast continued to run straight a moment. Both children gasped when they heard another wall crumble and they looked up, a vent or a hall or something was above them that they could escape through. The monster moved towards them, four arms reaching out to grab them, "You've tricked me for the last time!" Mabel grabbed her brother under his arms and shot her grappling hook straight up, as soon as they started launching up with a scream the monster's hands grasped the space they were just a moment earlier. The monster took no time at all chasing them upwards further into the Fearamid, growling the whole way up.
The kids kept running and running, the monster's lair getting more and more maze like the further they ran in. Eventually they both gasped as they came to a wall, "I'm starting to think there's no way out of here," Dipper's voice was light and breathless.
"Like Grunkle Stan always says," Mabel's voice was a bit more steady and far more optimistic, "when one door closes," she grabbed the flashlight from her brother, "choose a nearby wall and bash it in with brute force!" She used the flashlight on her own hand, the blue light making her fist huge and cartoon like. She grunted with the effort of swinging her fist towards the wall but with a solid yell of frustration her fist broke through the wall blocking their path to escape.
Dipper made a victorious noise while his sister shrank her hand back to a normal size, "Now let's round up the townsfolk, and together we can defeat…" he trailed off as they looked to the scene below them. "Oh, no!" four of the henchmaniacs had surrounded the townsfolk that had escaped, they were too far away to hear anything except the sound of their evil laughter. Teeth ended up eating one of the gnomes as well, electing a gasp from both of the twins, "Oh, no!" Dipper repeated again."
"Peek-a-boo!" Bill floated up behind them, his monstrous form back to normal and he levitated both the children off the ground with his eye emitting a bright yellow light, both children screamed in horror.
Bill returned to the throne room with both children clutched in one hand, "Alright Ford, time's up!" Even as the demon stood up straight both children struggled in his grasp, "I've got the kids!" his shadow loomed over the older set of twins. "I think I'm going to kill one of them now, just for the heck of it," Bill brought the younger set closer to his face, Dipper was punching his hand and Mabel was desperately trying to get out of his grip. Bill closed his eye and when he opened it red light in the shape of a pine tree illuminated the kids, "Eeenie," another blink, this time his eye revealed a shooting star, "meenie," his eye blinked again showing the pine tree, "minee…"
"Wait!" Mabel and Dipper had stopped squirming, but Mabel held her hand out to the monster. "If you're going to kill one of us now, it should be me," her voice was soft and thick with unshed tears.
"No! Mabel what are you doing!" the boy grabbed his sister's shoulder and tried to turn her towards him.
"It-it should be me Dipper," this time nervousness crept into her voice, her eyes avoiding her twin's.
"But why? Mabel, you can't sacrifice yourself to him! I need you. We need you to defeat him," Dipper pleaded with his twin, shaking her shoulder ever so slightly.
"Dipper, I'm the reason Bill is here. I gave him the rift," Mable turned away from her brother.
"What?" Dipper blinked at his sibling, despair filling his voice. "You would never give it to him, if you knew who he was. I know you Mabel," his voice took on the pleading tone again.
Mabel's shoulders curled into her body slightly, "I wasn't sure about it but I still handed that thing from your bag to the time traveler guy." Her hand gripped the sleeve of her sweater, "I'm sorry Dipper. It's my fault."
"Then I'm just as much at fault! I should have told you what Great Uncle Ford and I were doing. I should have trusted you the way you trust me. The way you trusted Stan when we all thought we had no idea who he was," he rested a hand on her shoulder. "Mabel you had no idea what the rift was, I was so worried you had tripped and it smashed," he rubbed his arm slightly, "I wanted to run into the forest right away but I listened to Ford and went after Bill instead. I'm just as guilty as you are for all this."
"I wouldn't have told me either," her eyes watered and she looked towards her twin. A small sniffle, "I'm such a klutz, and I probably would have broken the rift-thing earlier."
"No way Mabel," Dipper offered her a soft, sad smile, "I tried to shoot Ford with the mind erasing gun. That's pretty dumb, and I usually only help him by messing up."
A small sad laugh escaped her, "You're smart though Dipper, that's why Ford wanted you as his apprentice. I'm just the dumb twin."
Dipper frowned, "No Mabel, you aren't dumb. I've seen you do some crazy things, spur of the moment, that's smart. I always panic and mess up."
"But you're serious about things, I'm just silly," a sigh escaped her as her gaze shifted away.
"Without that silliness we would have never found Quentin Trembley, let alone escaped. I would never have been able to do that on my own," Dipper gave a soft rueful laugh.
"We got caught because I was silly," she crossed her arms.
"It would have taken me forever to crack those codes," he crossed his arms and held them in a defensive way. "Everyone loves you Mabel."
"That's not true.
"You kid's almost done, I'm getting bored," the large hand gripped the children tighter.
"Pick me Bill," Mabel turned her tear filled eyes towards the yellow demon's larger eye.
"No way! Pick me!" Dipper turned his furious gaze towards their impending doom.
"Hmmm," Bill tapped just under his bowtie in thought, "Shooting Star makes a good point."
"No, you should pick me, I know stuff from the journals!" Dipper's voice came out a seething hiss.
"No, me. If everyone loves me like Dipper says it'll hurt everyone more. You'll get what you want," Mabel looked away, down towards her two great uncles held in the blue pyramid cage.
"She's got a real good point Pine Tree," Bill seemed to perk up at Mabel's words.
"No she doesn't pick me!" the young teen slammed his fists against the hand holding him and his sister.
"Where was I again? Oh yeah," Bill closed his eye, opening it to reveal red light in the shape of a shooting star. "You," the demon's free hand moved to snap his fingers.
Bill's arm shook with the force building between the finger and thumb. Just before the snapping sound was made Great Uncle Ford called out, "Wait!" The singular eye was drawn from the younger twins to the older twins, "I surrender!"
The hand around the young twins loosened, "Good choice," the pair fell through the air and landed with a groan on the Fearamid floor. The demon immediately started shrinking back to his regular size floating towards the cage holding the elder twins.
Stan grabbed Ford by the front of his jacket, "Don't do it Ford! It'll destroy the universe!" Stan shook his twin roughly, trying to plead with the other man.
Ford's hands gripped Stanley's wrists, "It's the only way!" he yelled back at his twin, trying to make him see reason.
Bill's laugh interrupted their small spat, "Oh even when you're about to die, you Pines twins just can't seem to get along!" A snap of Bill's fingers blue flame engulfing the hand, the cage slipping back down into the floor. Glowing arms wrapped around Stan and dragged him into a kneeling position on the floor, a small groan the only thing escaping him.
Ford turned his worried glance away from his twin and towards the triangle. He frowned and pointed at the demon, "My only condition is that you let my brother and the kids go," the single eyes followed Ford's finger towards Stan.
Bill raised his arm in contempt, "Fine."
Dipper tried desperately to pull himself towards his great uncle. "No, Grunkle Ford! Don't trust him!" Mabel could only stare with her mouth slightly agape.
Ford turned his gaze from Stan back to the demon, his face set with sheer determination. He closed the small distance between him and the evil being in front of him. "It's a," Bill's hand shot out towards Ford, "deal!" his hand lit up with blue flames.
Ford slowly reached out and took the offered flame coated hand.
Well I think that was a good place to leave off! I would love to hear feedback on how I did! Let me know! I'll love you for forever! Thank you for reading and have a wonderful day!