He looked at you and that was all he had to do. He had a chocolate hair and shiny eyes, he was wearing a very peculiar tuxedo, not alike to the other ones people were wearing, it made him different, as he already was.
He caught your attention in such an odd way, a way that any boy had ever got. He was so mysterious and weird, you wanted to get to know him, but you also wanted to decipher him by yourself, he was a puzzle standing in across the room, you were curious, hesitant, you were got.
He smirked at you, and you were done. He seemed from another world, another dimension, he was different from anything you have ever seen, his stare felt differently to any other when it reached you, his smirk was as peculiar as he was, you felt so many feelings it would be hard to describe them all.
The warm inside was comforting, but at the same time, something inside you told you not to talk, not to stare, something inside you told you that he was no good, something inside you was afraid. You were into an internal fight to decide what to do. A part of you were saying: "go" and another part begging you: "don't".
How could one simple human being do such a thing? How could one simple stare at a party make you act like that? But what could you do? You had never felt so attracted by the unknown, by the unsure, you wanted to know him, to decipher that odd creature glancing at you, though you were so insecure about it.
What could go wrong? Millions of things, you weren't the paranoid type, but that glance could bring that characteristic to you. That one weird glance in a lame party brought so many faces of you that you didn't even know. The paranoid, the confident, the curious... You were no longer the boring person you thought you were, you were unstoppable, you were unbreakable.
You took a deep breathe and walked into his direction, he didn't seem surprised by that action, he smiled, and lord, you couldn't believe it, but his smile was as odd as he was.
"Hey there" he said.
As you got to meet him, you realized that knowing him didn't exactly changed the way you see him, he was still that puzzle.
He was so peculiar it even freaked you out sometimes. You didn't know what you were doing anymore, you felt lost in an ocean, but you honestly didn't want to be rescued, you wanted to stay there.
As time went by, you ended up getting to know the city of Gravity Falls better, and that meant getting to know the people who lived there.
You soon noticed the people who you would never be friends with, people as Pacifica Northwest; and, in one day, you ended up in the Mystery Shack, to meet the Pines family.
It was odd how they looked so familiar, the girl, Mabel Pines, reminded you of Dipper, but her eyes weren't shiny, they were brown, simply brown, they didn't have the weird factor that made your Dipper so interesting.
You've heard about that family once, they had lost someone, apparently one of them had go missing for such a long time, nobody knew where he was, nobody knew much about him, and who did, never dared to speak about it.
Time passed and you only got closer to Mabel, she was just so nice, even though she had passed through so much, it was impossible not to feel attached by her happiness and life style.
"I had a brother" she said suddenly, you glanced at her.
"You don't really have to..." You said in a careful voice, but she interrupted, shaking her head, smiling.
"Nah, don't worry" she made a pause "he went missing. Long story. It involves demons and... It's been two years, I haven't heard of him since. So I stayed here in Gravity Falls, I need to find him, you know. Even if I don't find him, I need to find who made that to him and destroy it. Not only for me, for him, for family, but for the human kind"
**********
"Oh, I am really sorry about this. But you were too close to destroying me, and I guess we both don't want that, right?" You heard Dipper's voice. You slowly opened your eyes to find yourself confined in something that looked very similar to a jail. You glanced at Dipper, his eyes were shinier than usual... More yellow perhaps?
"What are doing?" Your voice was barely heard, it was so low and so unusual, something had happened, he had done something to you and you couldn't figure out what. You didn't know why you were there, why he was acting like that, and what have happened.
"I am stopping you from stopping me" he answered smiling. "When you come back to your senses, I will let you free"
"Let me free?" You asked shaking your head, where have you put yourself in?
"Sure. When you finally realize the importance of what I am going, then honey, I will just let you free, so you can be at my side in the new world"
"The new world?"
"You can be so dumb sometimes" his smile was different, more psycho "I like that"
"I am not dumb" you said not actually sure if you believed it.
"Sure you're not" he laughed. "Perhaps I should explain it to you, then?"
"Just say it!" You spoke a little louder.
"The new world, the world I am creating, it will be a huge freak party! Everybody who is a weirdo will be finally in the higher parts of society, and I will command it all"
"What" your voice cracked.
"Yes. And you will be at my side, won't you?" Before you could even answer, or at least process what you've heard he laughed at you again. "Of course you will, sweetie, why wouldn't you?"
"Dipper, what are you..." You shook your head. "You're not Dipper!" You screamed as tears started coming, you didn't care, you wanted answers, you wanted to start it all over.
"Bing Bong, there you go! There is no need to call me Dipper anymore, maybe you should call me Bill, perhaps Bipper. I guess Bipper is cooler, right?"
"I..." You took a deep breathe, did you even have a choice? "Bipper is cooler" you whispered.
"Let me know when you're back to yourself" he said making his way to the door.
"Wait!" You screamed, making he stop instantly, he slowly turned around, that psycho smile, that shiny eyes, that's what your curiosity lead you at. "Explain it to me. I need to know what is going on"
"I already explained it to you" he answered shaking his head. "Look, kid, I"
"Haven't I already told you not to call me 'kid'?" You said automatically; he used to call you 'kid' sometimes, and you just didn't enjoy it, so you always had to tell him to don't.
"You are a kid in mind"
"Let me go" you begged, he was no longer the Dipper you thought you knew, he had tricked you into believing he was someone, while he was actually not.
"Just say you will be by my side" he said getting closer to you.
"By your side? Help you in your plan to destroy humanity?" You asked disgusted.
"Have they ever do something worthy to you? Something that you are thankful about? Oh, oops, no, they haven't, why are so worried about it then?" He asked angry. "Will you give up everything we worked for"
"you worked for" you said correcting him, he shook his head in denying.
"You helped me. You helped me and you don't even know it, do you?"
"I..."
"Everything we worked for, together, just to save people that always hated you? That never did one single worthy thing for you? That never cared? Are you going to betray me? I, the person who stayed by your side through all this time, just to save people that were always mean to you?" He asked looking deeply in your eyes. He smiled as he realized he was getting you into the plan. "Come on, baby" he said tenderly "I will let you choose a few people to live, to be with us. I will let you save some people, if that's what I have to do so you stay by my side"
"Do you promise?" You whispered, aware of your sins, aware that that was the only chance to save a really small part of humanity, that was the only chance, or that or everybody would be dead.
"I promise" he answered seriously. "We can even make a deal if you want"
"A deal?"
"Yes. If I don't let you pick some people to save, you will have the power to defeat me" he said reaching his hand to you, and you hesitantly, not sure if that was the right thing to do, but doing it anyways,  shook his hand. "Not that you will do it right?" He gave you a psycho smile.
"I won't" you whispered. 
"Then the deal is done"

••••••••••
I am so sorry if this let you down, but I am kinda happy with how this turned out. I mean, you can't have a lot of story in a scenario, though I would be really interested in writing an actual fanfic based on this little one shot. Let me know what you think!
I am planning the next one to be a Wendy X Reader, tell me what you think, and/or if would like to request a different character.
I can also write Character1 X Reader X Character2. Whatever you prefer :3