"Say, kid would you like to make a deal with me? I give you all the knowledge that I possess, and you give me companionship, for all of eternity." he offered, holding out his hand to the boy in front of him.
"I stay alive. You don't hurt me. You don't mess with my memories. Absolutely no possessions. Ever. Got it?" the boy asked, gripping his book tighter as he readjusted his hat.
"Yeah, sure. Deal?"
"Deal."
They shook hands, and were both temporarily enveloped in blue fire.
"So, kid, in order to stick by you, I should probably make a mea-, uh, body, huh?"
"Sure... um, what do you have in mind?"
"I dunno, maybe taller than you. Obviously, yellow. Maybe, over the eye... you call it hair, right? Yeah, uh I dunno, haven't been human since... 87?"
"1987?"
"No, the year 87."
"Ah. Well, how about, slightly taller than me, uh, 5' 4", a bit buffer, bright blond- uh, yellow hair with blue eyes, hair over your eye, grey jeans, tannish- light brown skin, white shirt, blue vest. Can you make that?"
"Uh, sure. One sec, kid." His body began to glow, growing and changing into a human shape. The blue glow dissipated, leaving the boy's exact specifications in it's place. "Whaddya think, Dipper? Look okay?"
"Uh, yeah. Looks good, Bill." Dipper supplied, giving a thumbs up. "Say, uh, make the shirt a size bigger, and, maybe a half inch shorter?"
"'Kay." The glow enveloped Bill again, and he reappeared with the changes. "Better?"
"Better. Now, you've probably made some enemies; being a dream demon and all, so how about... William Cedar? Will, for short. Likes puzzles, so I call you Cipher. Does that work?"
"Eh, sure. Works for me, kid. So, what, do I live in a cabin in the woods? What's my story?"
"How about a treehouse? I found one in the woods, in good condition. You can probably customize it how you want. We met in the woods, you were losing a fight with... a Wendigo? No, something smaller... uh... oh, a Gremloblin! I heard your scream, and drove it back and helped you through your worst nightmare. You ran into me later, and we became friends. We'll introduce you in... five days? Tomorrow and Wednesday, I'll make up a bad excuse to sneak into the woods, and by Friday Mabel won't buy my excuses anymore, so I crack and say I made a friend in the woods, she'll butt out because I have no life, and she'll meet you soon after. I actually should get going back."
"You talk a lot, Pine Tree. I'll find the treehouse and customize it, you get sleep for your weak human body." Bill said, and began to float away.
"It's to the west. See ya."
"Bye, Pine Tree."
He readjusted the straps of his backpack, striding nervously to the door while looking around furtively for people.
"Hey, Dipdop! Where ya going? Why's your backpack look so full?" his sister asked, popping in front of him when he reached the door.
"Gah! Mabel, you scared me! I'm... just going out. No other reason. Can't I just go for a walk if I want to?" he lied, trying his hardest to make it seem like he wanted it to be believable.
"Yeah, sure, whatevs Dip-dot. I'll find out eventually. You know I wi-ill~" she singsonged, stepping out of his way to the door.
Dipper rolled his eyes. "Sure, Mabel. See you before dark."
"See you! Have fun, but don't get hurt, Dipper. I'm not breaking out the medical kit today."
"You won't have to. Bye!" And Dipper was off, slamming the door behind him in his rush to leave.
Mabel just put her sweater-covered hands on her hips, shaking her head. "You're gonna get into trouble, one of these days, Mason Dipper Pines. Sometimes, I just don't-" her voice cracked a bit, "-don't know what to do with you... little bro.." She wiped a tear from her eyes, and spun on her heel fiercely, a massive smile on her face. "Now, let's go through all Dipdot's belongings to make him really paranoid!" she cackled madly, racing up the flight of stairs to their shared bedroom.
"I came as soon as I could get away." Dipper reported, breathing heavily.
"Man, kid, you really need to bulk up your body, or at least get you some more endurance, or the magic I wanna teach you's gonna get ya killed." Bill commented, picking nonexistent dirt from underneath a black nail. He floated maybe three, four feet off the ground, yet somehow seemed to tower over Dipper.
Dipper scrunched his eyebrows in confusion. "Magic?"
"Yeah, you know, how I float, and change back and forth from a sentient triangle to a human, how I make deals and set shit on fire. The typical stuff." Bill explained nonchalantly, flicking some more nonexistent dirt off his immaculate jeans. "What did you expect? That I was gonna teach you the secret to the universe just like that?" A loud snap echoed his last word, and suddenly they were on the ceiling of a house covered in black and white patterns, grey furniture dotting the space. "Whoops, didn't mean to do that. Here." Bill snapped his fingers again, and they were suddenly back inside the treehouse, and Dipper felt like his insides had been rearranged.
"So, uh, I'll be able to do the same stuff... you can do?" Dipper asked, fighting off a wave of nausea.
Bill shrugged nonchalantly, twirling his cane. "With enough practice, maybe. You have immense magical reserves, kid. The magical world loves you, even more than my last apprentice."
"Last apprentice?" Dipper clutched his book a bit tighter beneath his vest.
"Yeah. Towards the end of our... partnership, he couldn't handle the strain the amount of magic he could use gave his brain, and snapped, becoming increasingly paranoid. He tried to build a portal, to bring my dimension's magical energy into yours, but he ended up getting sucked in instead. In fact, I think you're holding one of his books. He wouldn't show me the third one, blocked me out of his mind, and began to grow paranoid at every moment, convinced I was out to get him. I tried to help... but it was too late. His mind had already snapped and reformed, and he couldn't be reasoned with anymore. He's my biggest regret, Sixer is, and I wish I could have saved him."
"You-you mean that the writer of these books, you-"
"I tried to teach him like I did you, but he couldn't handle his magic well enough, and it made him paranoid. He eventually turned against me, and then he disappeared from my sight completely. I can't sense him anymore."
"So that's why he wrote that." Dipper mused, flipping through his book. He ended on a page marked over and over in red ink, and showed it to Bill. "He wrote 'Trust No One' on this page, the one right before he details how to summon you."
"That makes sense." Bill clapped his hands, and suddenly they were in a completely white space, devoid of anything but the two of them. "Now, let's get started. That topic wounds the small amount of emotions I possess, and I don't like to talk about it for long. So, first thing. I'm thinking, let's get rid of a bit of that hyperlogical thinking of yours. Why? Because we're working with different rules here, not the ones you're used to."
"What do you mean?"
Instead of answering, Bill reclined. "I'm on a couch."
"Huh? No, you're not." As if to prove his point, he waved his hands underneath Bill, and met no resistance.
"I am. You just don't believe I am. This is what I meant by your hyperlogical thinking, kid. You need to think that I've got a couch under me. Try it."
"Okay." he replied, rolling his eyes. "Okay, it's... a light blue leather couch, worn but not cracking, with brown wood legs."
Dipper felt a sensation akin to the clicking of a lock, and then a flood of power; as a couch with his exact specifications appeared underneath Bill.
"Great job, kid! Alright, what's next..." Bill thought for a second. His hat temporarily transformed into a lightbulb as he shot up from his previously comfortable position. "Got it! Try to make some fire!"
"Uh, what? Like you do?"
"It doesn't have to be blue, but yeah, basically." Bill noticed the confusion written on Dipper's face, and decided to elaborate. "Try... um, gathering your magic into your hand, and then creating a spark, like lighting a fire and using the magic as kindling."
"Uh, okay." Dipper concentrated, trying to find the flood of power that he'd felt before, but nothing came. He sighed, frustrated.
What about trying something else? Imagination was always more Mabel's thing, but Dipper supposed he could give it a try.
He imagined a lighter, how it was lit by friction creating a spark that lit up. Friction. Let's try that!
Dipper snapped his fingers, a navy blue blaze appeared in his hand. "There! I did it!"
"That you did, Pine Tree. Nice job." Bill readjusted his vest, and floated off the couch completely to lay on his stomach above Dipper. "What did you think of, feel? It's important for me to know how you process your magic."
"The magic itself feels like... a tidal wave, sort of, rushing out to do what I want it to. And, well, a spark is created with a lighter in response to two metals rubbing against each other, creating fiction, more or less, so I used the friction of my fingers snapping to ignite the magic, creating fire. Is... is that too much thought?"
"Hey now, kid. I never said you couldn't think, you just had to think a little less like there were rules you couldn't break, and more like the rules were yours to make." Bill quipped, flicking Dipper right on his birthmark. "That's how magic works. You break the rules and make new ones. Like you, breaking the rule of 'metal creates a spark' and made the rule 'friction creates a spark'. You see?"
"Yeah, I do..." Dipper rubbed his birthmark a bit, then snapped his fingers again. The dark blue flames reappeared, stronger, and Dipper couldn't help the smirk that twisted his lips. He let it go out, and then focused on the area in front of him, holding his hand out. "Let's try something else."
In front of him, a large torrent of fire shot out, scorching a previously invisible wall maybe thirty paces off. "Whoa, it worked."
"Sweet, kid. That's actually impressive. What rules did you 'fix' this time?"
"I made a rule that says I can manipulate fire that comes from my hands at will. And another that says the fire I make isn't affected by the elements or any natural law." Dipper said proudly, a miniature inferno circling around him as he sat down cross legged on the floor. "Are there any rules I can' break?"
"There are only a handful. Death is permanent, anything related to the bringing back of souls is impossible and should not be tried, not even by a primordial demon of chaos and dreams like me. Love can never be truly forced by magical means; love potions cause infatuation, but true love cannot be made with magic. That law can only be broken by the cherubs, and only rarely. If they use it too much, or for selfish reasons, they can get stripped of their powers and destroyed. Magic cannot be used without drawbacks, all beings, living or nonliving, have a magical threshold that cannot be crossed, or adverse effects could very well destroy them. There are ways to expand magical thresholds, but everything has a limit." Bill explained, turning onto his back.
"Wait, you said... here the magic used wouldn't have any adverse effects on my body?"
"I'm using my magic to stop that from happening. When you wake up, you're going to have a nasty headache, but nothing else. If you tried to use magic in your world to the level of potency you can here, without limitations, you would combust. Here, we can exercise your magic, bringing your natural threshold higher. You can also get your threshold higher by working out a bit. Cut down a small tree and deadlift it until it's too easy, then get a bigger tree. That stupid bodybuilder stuff you mortals have is nothing more than showing off, they don't have endurance for shit. Run a lot, and lift trees." Bill advised. "It's gonna look like you're gaining a bit of fat, but it's more muscle than that."
"Gotcha. Hey, how long have we been here?"
"In your world, about two to three hours. An hour to sunset."
"Ah. I should probably be heading out soon, huh?" Dipper suggested, not really wanting to leave.
"Yeah. If you want more training today, clear your mind before bed and try to think of me manifesting in your room. If the world goes grey, then I'll be there in a second." Bill suggested. "Alright, now I'm gonna wake us up, so get ready for the headache of your life, Pine Tree."
"Can't wait."