Note: Special thanks to my beta reader, DirectorHachi, as well as MiniJen, author of "Universe Falls," a Steven Universe/Gravity Falls fic that heavily inspired this.
Chapter 1: The Wand
Once upon a time, in a mystical land known as Mewni, a very special day had come. A whole kingdom waited in either anticipation or dread for the event that would change the fate of the realm forever.
But while many were content to sit back and await what was to come, one individual (and the army that served him) had other plans.
Hidden in the cornfields, a stumpy, green, beaked creature watched and waited. Using binoculars, the monster spied on the figure central to the impending event, currently wandering the fields with a sheet of paper in her hands.
"Come on...come on, you idiotic princess, turn left!"
Soon enough, she turned to her right and noticed something among the corn. Grinning, she dashed off to find her reward.
"Eeeeexcellent..." the beaked figure muttered. "EEEEEXCELLENT!" he burst out much louder, raising his arms to the sky. "We've set the perfect trap! Soon, Star Butterfly will be in our clutches, and the queen will have no choice but to relinquish that wand to me! Then, I will have everything I've ever wanted! Height! Muscles! Unlimited food! TOTAL UNIVERSAL DOMINATION! YAHAHAHAHAHAHA!" The tiny aspiring warlord broke out into a mad cackle, not noticing when another figure began laughing in a more benign way right next to him.
"Hey!" the figure suddenly said, "Maybe you could also wish up some magic medicine to fix you and your friends up!"
"Yes, yes, that's a good—" the short figure responded, still chuckling—until he suddenly stopped. "Wait a minute—" He turned to his side, seeing a relatively short human-like person—still much taller than him—with blond hair and wearing a regal blue dress. The princess pulled a large mace out of seemingly nowhere and smashed him in the face, sending him flying a short distance.
"Ugh—OWOWOWOW!" the monstrous midget yelled out, holding the area of his face bruised by the mace. "How...how did you find out what was going on? That was the perfect trap!"
"Well," said Princess Star Butterfly, "I saw a bunch of your monsters who were too big to hide in the corn and I heard you madly cackling. Oh, and this note? Terrible." Star held up the note, written in sloppy, nearly illegible text.
"Dear Star Butterfly,
Congrajulations! You have won the Mewni Corn Lottery! Come to the cornfields at therty minites to noon to claim your prize!
Sincerely, The Mewni Corn Farmers' Union (Not Ludo)"
"Seriously, if I want corn, it's not like my family's gonna run out of money," Star finished matter-of-factly.
"Grrrrrrr!" Ludo growled, still clutching his bruise. "MONSTERS!" he yelled out. Immediately, seven bizarre beasts emerged from the cornstalks and stood beside their leader. "GET HER!"
Star, still clutching her mace as the monsters rushed towards her, grinned. "Looks like it's gonna get a little wild here!"
Star dashed forward herself, swinging the mace at a five-eyed fleshy pyramid, making an impact that would have knocked out half of his teeth if he had any. As her victim fell to the ground, Star swung her weapon in a circle, bashing four of Ludo's other minions—a goat with a turtle shell, a muscular frog, a bearded deer-creature, and a three-headed scorpion—multiple times.
As they, too, fell to the ground, Star heard a shriek from above—a large sugar glider, attempting to spit icicles at the princess. As all his shots missed, Star lept up to clobber him, too, with an upward strike, before swinging downward to smash Ludo's final minion, a bear with a unicorn horn, in the head, breaking the horn in the process.
As Ludo stared, open-mouthed, Star pulled out a stopwatch. "WOW, that's my best time by far for seven minions!"
Beginning to seethe, Ludo angrily shouted, "That doesn't count! You had a weapon on hand!"
"Eh, fair enough. Anyway, Ludo, this was fun, but I've gotta get back to the castle. Big day, you know! Byeeeeee!" Star then started to skip away, not giving Ludo a second thought.
"What...but...YOU'LL PAY FOR THIS!" Ludo yelled at the departing princess. "Seriously, you'd better pay for this! Pyraflesh's medical bills are high enough, and you broke Bearnicorn's horn again!"
"Well, Star, you excited?" asked a cheery, slightly nasal voice.
"You bet!" replied Star, somehow even cheerier than her conversation partner. "Ooooh, I can't wait, I can't wait, I can't wait! This is it! I'm finally gonna get that wand! Think of how many amazing things I could do with that!"
"Well, first you have to get the thing!" said Star's friend, a floating unicorn head speaking through a magic mirror.
"I know, I know, I'm just so excited!" Star replied, just before a royal servant opened her door.
"Princess Star, the ceremony will begin in five minutes. The queen and king expect you to be prompt."
"All right, Manfred! I'll be right down!" Star said, to which Manfred nodded before closing the door again. Turning back to the mirror, Star said, "Well, I gotta go! See you, Pony Head!"
"See ya, Star!" replied Pony Head before cutting off the connection.
Down in the room where the ceremony was set to take place, two ornately-dressed figures—Queen Moon Butterfly and her husband, King River—stood in wait at the head of the crowded room, waiting for their heir.
Moon took a deep breath, which River noticed. "Calm down, my dear," he said, "I'm sure everything will be fine."
"Don't be too sure," Moon responded. "This wand,"—she subtly raised a regal scepter topped with a blue crystal heart—"is a tremendous responsibility. If it falls into the wrong hands, it could spell the end of the whole universe. Every kingdom, every realm, every dimension. I'm honestly not sure if Star is capable of handling this power."
At that moment, the doors at the other end of the hall burst open, revealing a widely-grinning Star Butterfly, literally bouncing in anticipation.
"I hope we don't come to regret this," Moon said.
The next day…
Moon finished reading a semi-well-written report, filled with a mixture of legal jargon and angry complaining. On the report was a picture of Star, clutching the wand—now appearing as a short rod topped with a circular head, which was adorned with a golden star and wings on the side. Moon dropped the report into an open flame that happened to be nearby. "Well, that's one hundred twenty-one reports of property damage. I believe that's a record for the kingdom."
River sighed. "I know that, but what do you plan to do?"
"We need to find a place where Star can practice her magic safely. A place where she can learn how to be more mature and responsible. A place where she can be guarded by people we can trust.
River had a start. "You don't mean..."
Moon nodded.
"NOOOOOOOO!" Star yelled. "Please! I'll do anything! I'll work the corn fields! I'll scrub all the floors! Please don't send me to...to..St. Olga's Reform School For Wayward Princesses!" Star's hysteria led her into a bout of hyperventilating and wailing that even the surrounding guards flinched at.
"Sweetheart, sweetheart, calm down!" River interrupted. "We're not sending you to that place!" Star ceased her whining, not noticing Moon make an apprehensive glance to the side. "But we are sending you away someplace—you're going to the dimension known as Earth!"
"Whaaaaaat?!" Star blurted out, her terror replaced with confusion. 'But there's no magic on Earth! How am I supposed to practice my magic in a place where there isn't any magic?!" she gasped.
"Actually, Star, there is magic on Earth," Moon said. River nodded as Star gave a perplexed look, prompting the queen to continue. "Some time ago—only a few years before you were born, at that—I went on an excursion to Earth and encountered a quartet of strange entities that our scarce records of Earth never spoke of. After I helped them take care of a problem they were facing, I became acquainted with these...Crystal Gems, as they called themselves.
"These beings possessed a sort of magic of their own, and with their residency in a dimension as relatively peaceful as Earth, I have determined that they will be the perfect wards for you as you are trained in proper use of the wand." Moon gave a brief nod, finished with her explanation. "Any questions?"
Star looked at her with a blank expression at first before bursting out again. "Ooh, what kind of magic do they have? When you say they're crystal, are they like the ones in the Crystal Dimension? What's Earth like? What was the problem you helped them with?"
Moon gave a brief, reserved sigh as more questions poured out of Star's mouth.
Three figures walked along a beach—one muscular and red, one short and purple, and one slender and white. "Ugh, those stupid bug things were so annoying. We couldn't even find out where they came from! Talk about a bummer of a fight," the purple one complained.
"Still, they seem to have stopped coming for now," the white one replied. "I do think it would be more wise to go find the mother, but...okay, Garnet, what is it you need us for?" she continued as the red one, leading the others, ceased walking.
"We have a visitor coming," Garnet answered.
Before either of her friends could comment, a shocking—but not unfamiliar—sight appeared. A large blue portal, reminiscent of a tear in fabric, materialized out of seemingly nowhere. From out of the portal emerged a regal carriage pulled by horned horses—unicorns, creatures the Crystal Gems had only heard being spoken of.
Alongside the carriage were several guards clad in armor. One of them came out in front of the Gems and made his declaration: "Announcing the arrival of the great, illustrious ruler of Mewni, Queen—"
"Oh, that won't be necessary," the queen said as she emerged from the carriage. "They're old friends, after all."
The Gems perked up upon seeing Moon. "Why, Queen Moon!" Pearl said. "It's so nice to see you again!"
"Same to you, Pearl." Moon turned to the others, greeting them as well: "Garnet, still a pleasure. And Amethyst...my, have you changed your attire?"
"Long story," Amethyst shrugged.
"To what do we owe the pleasure, Moon?" Garnet asked.
"Well, I have a favor to ask. Star, could you come out?" Subsequently, a figure about Amethyst's height (though more slender) bounced out of the carriage and darted over to her mother's side, making a formal stance that showed she was not comfortable with having to behave so uncharacteristically. Ignoring this, Moon again spoke to the Gems. "This is my daughter, Star. Due to her recent fourteenth birthday, I have bequeathed unto her the Butterfly magic wand, as per tradition."
"Wait...the wand you used to fight that monster twenty years ago?" Pearl asked, astonished. Moon nodded. "I...is that really safe? Star here doesn't quite...seem the type to handle such power like you did." Pearl motioned to Star, who had already abandoned her formal stance and darted off to summon a rainbow shark into the nearby ocean.
Again ignoring her daughter's unruly antics, Moon continued, "That is why I am here. It is imperative that she practices her magic in a dimension that is safe, isolated from the chaos that magic will often incite. Earth was one of the best examples of such a place, but it also has you. You have had experience with not only your own brand of chaos, but also a taste of what that very wand is capable of. As such, I have decided that you, the Crystal Gems, are the ones best suited to protecting Star—and keeping her in line—as she learns to handle this power."
Garnet nodded. "Okay."
"Wait, Garnet!" Pearl protested. "Shouldn't we think more about this? This is a rather big responsibility, and we have our plates full as it is."
Garnet shook her head. "We can handle it. We'll take her."
Moon's smile widened slightly as she nodded herself. "Thank you, Garnet. I'm sure that you are capable of making sure Star doesn't burn down another town."
Pearl sighed. "Well, I suppose you know best..."
Amethyst, meanwhile, was more upbeat. "All right!" she shouted, pumping a fist. "New houseguest!" She turned to Star, who was still playing with the wand by the shore. "Hey, Star!" she called out. "Why don't you show me what that thing can really do?"
"Oh, my," Pearl said, clutching the bridge of her pointy nose as Garnet gave a small smile. "Please tell me Amethyst can't use that thing."
"Indeed," Moon replied flatly as she watched Amethyst and Star enthusiastically introduce themselves. "Oh, by the way," she said, turning back to the other two Gems, "where is Rose Quartz? She should also know what she's getting into."
Garnet's smile faded and Pearl gave a mild flinch. "Well..." the latter hesitated, "do you remember that human Rose liked?"
The door of the beach house opened, prompting a young boy to turn away from the freezer and towards the people entering his home. Seeing a familiar face, he greeted with a "Oh, hi, Pearl! How was your walk?" Seeing an unfamiliar face, his brow furrowed. "Who's that?"
"This is Queen Moon Butterfly. She's an old friend," Pearl answered before turning to the queen. "Moon, this is Steven." She hesitated before continuing. "He's Rose Quartz's son."
Moon replied silently, with a confused, almost skeptical look. She glanced at Steven, as if asking him to explain. "Oh, uh..." Steven said, showing brief uncertainty before pulling up his shirt just enough to show his navel—which had a distinctive pink gemstone attached to it.
Moon's expression turned from one of confusion to one of surprise, as if letting out a silent gasp. She stared at Steven for a few seconds before turning her head, gaining a businesslike look, and putting her hand to her chin. "Hmm. This complicates things."
Notes: I've had this idea for a while now, but only started working on the actual writing...sooner than I expected, honestly.
Some of the story may have some discrepancies with how events occur in canon—this is done for the sake of complementing my original content and preventing as much of the story as possible from being merely rewrites of episodes with crossovered characters being thrown in.