Hello. I would first and foremost like to apologize to anyone who opened this chapter gleefully hoping that this story had been continued. You have every right to be disappointed by what you will receive instead, but I hope it provides some degree of closure or satisfaction to those who read it. This will likely be the last you read of my branching AU, and before I explain why I want to express my sincerest thanks to all my readers and reviewers past and future, the fellow writers who helped me refine my work and brought me joy with their own stories, and to the crazy folks over at TVTropes who have kept a dedicated page to my obscure little Salt Fic.

I'm sure I don't need to explain at length the disasters befalling our world at the moment, and like many of you my own life has been changed by the tragedies and insanities of 2020, as well as the general and inevitable march of getting older. While I have not lost my love for stories and fiction (in fact, I hope to publish an original novel at some point with the writing skills I have built within this talented community) responsibilities now rest on me that require too much time and attention to still leave enough over to continue this overly ambitious fanfic saga. I think I have known that this story was abandoned for months at this point but have only now been able to admit it, and I apologize for leaving you all hanging as a result. With this chapter posted, I want to reveal my plans and outlines for what I had intended for the future of this story, as some small consolation for leaving the work unfinished. In addition, I am severing all tenuous connections of ownership between myself and the original ideas within these fanfic. If anyone wishes to use anything posted in this chapter for their own work or even to adopt the AU as a whole, they do so with my full blessing.

So, all of this started (all the way back in beautiful 2017, wow) because I had fallen in love with the show Gravity Falls when it premiered on television, endured with intense curiosity through its agonizingly long, hiatus infested original run, and then felt gut punched and betrayed by an ending that everyone else seemed to be celebrating as a work of beauty but that i loathed. So, I decided to try and write a fanfic explaining how I would have wanted it to end. Along the way, other cartoons with a charming blend of surreal fantasy, surprisingly dark horror elements, engaging mystery plots and endearing, three dimensional characters attracted my attention for the same reasons GF did, and gradually became intertwined with the adventures of the twins as I realized how compatible they all were. The most obvious examples of this are Star Vs The Forces of Evil (which funnily enough had an ending that I really appreciated the gutsyness of while most people dislike it, the inverse of the situation with GF) as well as Rick and Morty, but besides those two plans existed to incorporate a large amount of Steven Universe material into the third act of this hypothetical saga and had I still been making plans when they premiered, The Owl House, Amphibia and Infinity Train would all likely have their places in this multiverse AU.

But I suppose it's inevitable that passion fueled by spite burns down at the end, and I think it would be an infinitely better idea to dedicate writing time and energy to an original work that could help provide a living versus venting my grievances against an ending I'll never change with unpaid work online. I would never change a thing about my time in the fanfiction community (and I have been writing fic a for a long time under a few different names to be honest. This wasn't even my first overly ambitious cartoon crossover...) and I think it has done wonderful things to help me improve as a writer and an individual, but times are changing and I simply think it is inevitable that I am moving on. So, rather than fight it, I'd like to thank you all one last time for everything before laying out, in no particular order, the story that was never told.

Thank you all for a lot of good, wonderful times.

I guess I'll start by explaining most things related to Gravity Falls itself, since that's where all this started before it was a crossover. The main idea i guess I wanted to take on and display with this story was was how the events of that magical summer would change everyone involved, and how horrible and unhappy it would be if everyone just pretended none of it was real and just left, like the ending of the show tried to tell us. How such events would inevitably change the twins, the Stans, the town and even the world.

Dipper was a character that, despite the show's best efforts, I found intensely sympathetic and felt was robbed of a happy ending when Mabel held him emotionally hostage to make him go to high school with her. In Gravity Falls, he had found an environment and a mentor that directly connected to his passions and held real potential for him, as opposed to an American High School, which in addition to being useless at preparing teenagers for the future are now literal death traps due to COVID-19. By the end of the show I wanted him to be happy, and completely failed to be convinced he'd be happy with leaving.

Mabel is odd to me, because the people who made Gravity Falls are clearly brilliant geniuses but at the same time, they have so little self awareness of how awful their favorite protagonist ended up. The specifics of this Broken Base have been argued elsewhere, so I won't drag up all the old points, but suffice to say Mabel had exhausted my sympathy for her well before the finale rolled around, but despite all that I don't hate her. Rather I'm just baffled and confused by the writing direction that clearly sets this deeply flawed protagonist (and I'm not saying Dipper isn't flawed, but he learns from and disproportionately pays for his mistakes) to have to learn about self-sacrifice and finally put her brothers happiness before her own as he always did for her then just swerves, has her get everything she wanted while keeping her role in starting the apocalypse a complete secret and going straight to a sickeningly saccharine ending that directly contradicts the themes of the Society of the Blind Eye episode. If the finale had shown Dipper actually leaving to stay with Ford and Mabel being mature enough to accept this, I'd sincerely have no problem with her. As it is written however, she's easily the worst character in this otherwise brilliant show and deeply drags it down.

With that said, the original concept of Three was meant to invert the sibling dynamic: Dipper has blossomed into a confident, happy young man in Gravity Falls, sharpening his natural intellect alongside Ford and feeling secure about his place in the future, while Mabel is the one who feels disconnected and is searching for validation as her family seems oblivious to her internal torments and insecurities. By seeing the consequences of her actions and the genuine improvements Dipper has made separated from her as well as by interacting with a few thematic foils (initially just Pacifica and eventually Gideon, but as the scope of the story expanded Mabel was also going to be forced to look in the mirror against Star Butterfly and Blue Diamond) I had always intended for Mabel to grow into a better person to her family and to herself, someone who has her own arc and can accomplish genuinely good things without dragging down everyone around her.

There were essentially going to be three story threads weaving through the town of Gravity Falls when the story was just about Gravity Falls, which would be portal missions to destroy Bill, Earth adventures into local phenomenon, and character threads.

-The Bill hunt would involve a bunch of fantasy or sci-fi original settings where each of the fragments has been working their magic to steal bodies and stir up trouble. I decided pretty much right after Multiverse Chase that I wanted to add crossover elements to this story and wanted to make the dimension they chase Bill to Mewni, so no real unexplored aspects on that front. In terms of over crossovers, the Steven Universe ideas will be explained below, but other Bill fragment ideas include him manipulating the main character of Amphibia by offering her a way home (only for her to immediately turn against him after the crew offers her a portal ride home), the main antagonist of Infinity Train season one by offering her the revival of the dead, and in a twist on the formula being captured and used as an arcane tool by the Emperor Bellos from Owl House.

-The Earth adventures were vehicles to explore the horrible and wondrous things the various magic items found in the Falls could accomplish, with my favorite being the horrifying potential of the copier crossed with the carpet, which I'm glad I was able to give its own side story. Most of the antagonists of these would be people drawn to the strange rumors and unexplained events of the town, which the traumatized citizens are simply not able to effectively cover up after Weirdmaggedon. Through either ignorance or selfishness these antagonists create danger and conflict that the Pines resolve while they learn more about the rules and limits of the magic. The distant finale of the fic was always going to be the now adult twins as incredibly wealthy and world renown employees of the newly organized Pines Institute, a breakthrough science and technology company that has cured the sick, provided clean energy to the world and repaired the environment through Weird Technology, a new field of practical science founded by the gloriously remembered Stanford and Stanley Pines, who have passed away from old age by them but will always be remembered for having changed the world. Dipper has dozens of patents and is married to the CEO of the company (Pacifica) while Mabel is head of public relations and a fervent human rights activist.

-As for the character threads, Pacifica was going to wrestle with her feelings of guilt and self-loathing until she finally loved herself enough to try and love Dipper, who has problems confessing to her for the same reasons. After Preston wound up dead as a result of dealing with Bill Pacifica's emotional turmoil revolves around the fact that she wasn't as sad as she thought a good person should be after her parents died, and actually feels liberated by their deaths now that she's been taken in by the Pines. Essentially, her thread was meant to more starkly illustrate the idea of it being toxic to invest love and respect into family members that don't love and respect you, which is what I think is the genuine problem between Dipper and Mabel. But, where Pacifica's parents were callous and sociopathic born into wealth monsters, Mabel is simply a spoiled brat who could improve if the universe would actually call her out on her shit for once and as such, Mabel and Dipper would eventually build a functional relationship between themselves while Pacifica eventually comes to terms with separating herself from her biological family completely, adopting the Pines as her family of choice and eventually proposing to Dipper, initially framing it as a business contract to more effectively sell his inventions easier but quickly breaking down in embarrassment and yelling she loves him, even though they've been dating for awhile at this point.

Ford and Stan would both be grappling with their mortality and morality a lot, Ford being exceptionally proud of Dipper, coming to see him as a son but eventually learning to teach him restraint as well as science and appreciating Mabel's talents more while offering her some advice. Stan would have to face the fact that he kinda is a terrible role model to the kids even though he loves them, spurned on by the growing realization he has that Mabel ended up becoming a pretty hardcore juvenile delinquent in high school with the tricks he taught the two. In addition, both would have more realization about how terrible their own parents were, and Stan would realize that it was pretty fucked up to cite his harshly abusive father in a positive fashion when trying to teach Dipper life lessons.

Soos would stay Soos, just being fun and lovable while doing an excellent job of being Mister Mystery. Wendy... was pretty much always on the verge of being written out completely. Her subplot with Dipper dragged on and on and on with the show, and then we found out Pacifica was a way better partner anyways. In life sometimes people come and people go, and not everyone you meet and become friends with is going to stay relevant in your life forever. Since Wendy had very little to do with the show's mystery solving and monster fighting, she'd gradually fall by the wayside as Dipper embraces his true passions, but she's still on good terms with the Pines family, they're just going in very different directions.

I was never able to cover it in the story but in this AU, Robbie and Tambry broke up and are kinda uncomfortable around each other going forward. As supplementary material introduced after the series finale, elements of Journal 3 and the comics were going to be introduced into the story piece by piece if I thought they made sense, so these two falling in love anyway once the potion wore off to absolve Mable of guilt didn't happen. I've always been on the fence about how far to take this plot to be honest, probably why it didn't get written in before the end. Like, should they just be vaguely uncomfortable with each other and Mabel, should the actual consequences be harsher but more realistic such as the two irresponsible teenagers impulsively having sex with each other while under the love potion only to feel violated and disturbed when it wears off, I wasn't sure. I'd be happy to know what you all think.

Gideon was going to return as a sort of climax villain to Dipper and Mabel's trouble with each other. I never bought his sudden turn for good in the finale, so his plot would involve him scouring the desert for the skull of Blendin Blandin (who eventually died of the old west disease he got while hiding from the Time Police after getting the Time Baby killed) to gain the power of the Bill fragment in his skull and going mad in the process. Gideon at this point would be an ugly, vicious monster who only cares about himself and is willing to use mind control magic to sculpt and violate his victims until they become his perpetually grinning, ever fawning servants to him alone, and he still wants Mabel to be his bride. While fighting him, Mabel is forced to confront the ugly extremes of her behavior (she is NOT as bad as he is, but they both have the same nasty habit of seeing people from a very selfish, self-serving perspective and by overcoming Gideon, Mabel is overcoming her toxic personality aspects before she becomes as bad as him) while receiving positive reinforcement from Dipper, who fearlessly and without hesitation aids her in this fight: This Dipper is willing to stand up to his sister and won't let himself be manipulated and exploited by her but he still loves her, and absolutely isn't going to stand by and let Gideon have his way with her.

As for Bill... he's a monster, through and through. Each quest against a fragment of him would be a fresh parade of cruelty and madness. There would be no redemption of lightening Bill, and any perceived kind actions he takes are purely to manipulate others, probably in a way that screws them over twice as hard down the road. The Bill of this AU, for all his eons of knowledge and impressive powers of magic, is a thug and an animal who wants everything that can feel to die screaming so he can dance to the sound. Totally unsympathetic, end of discussion.

My angle was always to continually play up his sense and scale of cosmic horror and inhumanity in as many disturbing ways as possible. Since he's physical, broken and threatened now the classic floating triangle is rare, so broken forms knotted together to walk as an animal, eternal dark skies cloaking a planet or swarm of insects he has collective control over are still chattering about like a greasy used car salesman with lots of colorful metaphors that occasionally don't make sense because of how many worlds he's traveled to and learned of and manipulated while alien biological horror writhes about. Worshipers or Bill or those possessed by him always end up dead or worse off for it, usually sporting a wide and creative array of self-inflicted disfigurements. Dipper at one point shoots a Bill cultist in self-defense and has a very serious panic attack at the sight of all the self-inflicted scars on the body.

Everyone should get a chance at killing a Bill piece. All the Pines family get their individual one to kill (Stan spent the rest of his life boasting that he's the only one in the family that killed him twice!) and are crucial as a team in defeating others, Eclipsa gets her own, Star and Marco destroy one together, Pacifica is probably the first one I'd cut from getting her own if they ran out but she takes immense satisfaction in helping the Pines beat him, but the MHC never succeed in destroying Bill. That's a rule, he outwits them every time.

Then, the magical world of Mewni entered the picture. Given that I had a lot less problems with the characters of Star Vs when all was said and done, this section will be more plot and less character outlines.

I was really surprised by how well Star/Marco and Dipper/Pacifica became a friend quartet, and I honestly loved writing them as a group. Despite both having similar romantic setups (smart but insecure dark haired boy gets involved with rich but emotionally troubled blond) the roles are mixed around a little: Dipper is the one who burst unwelcome into Pacifica's life and changed her life with magic and mystery while causing her to improve morally as a person, similar to how Marco was the one who actually got Star thinking about what Mewni had actually done to Monster-kind. It never really got a chance to shine but I really wanted Pacifica and Marco to have a really sharp character dynamic where they take solace over being the "normal" ones in their relationships, standing back and making sarcastic commentary while Dipper and Star go nuts over magic stuff. In light of the changes to Tom in the story, Dipper and Marco would be the really close bros in the story, and these four would absolutely go on double dates at some point.

As for the Underworld, well, it was probably the biggest lore change made to this AU since the original show tended to offer us little in terms of hard information. In this story, Glossaryck gave the Mewmans the wand as one move in his eons long chess game against Bill Cipher, so Bill created the demons of the Underworld and a royal demon family to rule them. Like Mewni however, corruption and stupidity eventually limited their abilities as pawns, with the demon royal family becoming horrifically inbred as time passed, greatly weakening their magic powers even as the cult of personality they developed over their subjects kept them on top. Queen Jushtine negotiating them into Mewni's sphere was also something Bill didn't expect, making him one of the few people in the multiverse to get one over on the dream demon without knowing it.

King Dave was originally a Mewman alchemist working to create anti-monster weapons to use against Toffee's rebellion for Queen Comet, but was imprisoned and slated for execution as a result of conducting horrifying experiments based on the lost works of Eclipsa and Solaria. When Comet was assassinated however knowledge of his secret projects was lost and he escaped to drift from job to job in exile until he wound up in an Underworld coffee shop and meet Wrathmelior and was finally driven to conduct the most forbidden ritual, locked away in Queen Eclipsa's deepest records: the summoning of Bill Cipher.

Bill first appeared to Eclipsa when she was young, pretending to be a sympathetic ear when she lost her beloved uncle and was growing increasingly distant from her mother due to her hidden relationship with a monster. He offered her knowledge and helped her develop dark spells, with the end goal being the promise of a dimension she and Globgor could escape to, where Hekapoo could never track them. In reality, he was tricking her into building a portal to the Nightmare Realm. Her imprisonment obviously sunk this, but Bill filed away the truth of the MHC's actions for a latter day.

When Dave summoned Bill, Bill easily taught him magic that could destroy the weakened demon royal family and make him the new king of the Underworld. Wrathmelior, the runt of the current generation, was the only survivor beyond Tom's incoherent uncle (who Dave essentially left alive as a trophy) and married Dave. She is the nominal ruler of the underworld but has little in the way of taught skills due to being neglected for most of her childhood. Many demons resent a Mewman being their king and a hybrid being their prince but protesting this is a good way to win an acid bath. Dave has always been envious of how easily the Butterfly royal family wields magic while alchemists like himself have to scrape and experiment and poison themselves to just to have crumbs of magic power. Studying directly under Bill, Dave's secret plot is to set Tom up with Star (no matter what either of them have to say about it), unify Mewni and the Underworld (no matter what either nation has to say about it) and then soul transfer himself into Tom and Star's inevitable child, finally giving him all the power and respect as a Butterfly queen, possession of the wand and unmatched political power.

Tom was intentionally raised to be a short tempered, power burning, self-entitled monster by Dave to facilitate the above plan, but his relationship with his mother is considerably healthier and the revelation that his father never saw him as anything but a tool for his own power rocks Tom's worldview, causes him to chill out and eventually make peace with Star and Marco, though they'd never become as close friends as in the show.

Toffee learned the secrets to destroying the wand by summoning and communing with Bill, who in turn learned the mechanics of the wand from Eclipsa. Other than that he's his own antagonist whose plan was never influenced by Bill: Toffee summoned him to get information and used his lawyer skills to negotiate a purely beneficial contract with the dream demon, which both impressed and annoys Bill to no end.

Holy Diver is basically a stand from JoJo's Bizarre Adventure (Agent Ferris's powers are similarly inspired by the stand Metallica from that series) that the Underworld weapon smiths made from the soul of the heretical pharaoh Akhenaten so Bill could use his spiritual connection to the land of Egypt to project the spirit there, where it would steal Soviet Union military surplus from the Egyptian military and bring the weapons to Mewni. The monsters are explained as having been enjoying a relatively good period of life under Ludo surprisingly, because he was such a non-threat that the Mewni military mostly slacked off and doesn't bother actively going out and crushing resistance and hasn't for awhile. They're still not living great, but it's a relative good time. With Toffee using Ludo to sack the capital however, many are frightened that retaliatory purges are going to be launched by Mewni soon, which is how the Underworld persuaded them to buy these new, advanced weapons to protect themselves from the purging.

Bill's plan with supplying weapons to monsters was an attempt to get at Hekapoo specifically and more generally conquer the dimension. As part of her job, Hekapoo keeps the Nightmare Realm on permanent lockdown, due to the invasive threat it poses to other dimensions. Similar dimensions of permanent lockdown are a vampire dimension, a dimension of perpetual yodeling and the dark realm of another Eldritch terror that I think was gonna be a Samurai Jack reference or something Lovecraftian. That's why you can't dimensional scissors to the Nightmare Realm and the portal to get there needs to be so complicated. Contextually: Ford did accomplish something incredible and very rarely matched in the multiverse, and managed to outthink all of Hekapoo's most complex defenses in his work.

It was way to much fun writing Ford bickering with the MHC. Also, Marco gets the above lore dump on dimensions and the Nightmare Realm for himself (and by extension, the audience) just by walking up to Hekapoo and asking. When other protagonist hold out on the lore for dozens of episodes, Marco just walks up and asks for it.

Maybe a little more expanding on Marco's changing perception of knighthood, but I honestly think I got the crux of this across in the story itself and am mostly cutting the knight training subplot, though the relevant characters from it would get appropriate appearances as Mewni military. He is unfailingly loyal to Star and believes firmly in her capacity to rule with kindness and justice. He knows a lot is wrong with Mewni but also appreciates the aspects of it he finds beautiful because he thinks Star can genuinely make it better for everyone. He gets teased/mocked for this overly romantic outlook a lot but never really loses it.

Star's relationship with Moon however, was not going to be good going forward. Star is increasingly invested in Eclipsa's way of thinking in this, which I always wanted to write as a little darker and more forbidden knowledge focused than canon went with but not enough to make her a full villain. They continue to work together against the very genuine and massive threat of Bill and the Underworld but gradually realize they both fiercely disagree on what is not even best for Mewni, but what is even right. The third act of the series would have featured this increasingly tenuous alliance between Star, Moon, Eclipsa and the MHC tearing completely as the question of what should be done with Mewni in the aftermath comes up, and Star is firmly on Eclipsa's side. Much quoting of Revenge of the Sith would occur, and Moon would bitterly lament that Star has destroyed their royal legacy, and that she should have sent her to Saint Olga's instead of Earth, which from Moon's perspective radicalized her daughter.

Though weirdly enough, even as she grows resentful of Star, Moon is always unfailingly polite to Marco. This is because she's heavily sexist by the values of Mewni: The duty of a woman's husband, her king in the case of women like her and Star, is to be unfailingly and unflinchingly loyal to and supportive of her ambitions and outlooks, and should assist their accomplishment and comfort with these things in all matters. Marco is simply being an ideal Mewman husband in that regard: going along with all of Star's decisions with all his might. She hates what her daughter has become but doesn't think Marco has the right to question her and thus respects his dedication to her. Was going to possibly work in a joke dunking on Mabel to the otherwise dramatic scene where Moon explains this viewpoint of hers. Of course, what Moon is too proud to admit is that a lot of Star's changing ideas about monster relations began with Marco, and their relationship is not nearly as one sided as she perceives it.

But uh, anyway, the end of this middle section of the story was gonna be the hero team losing incredibly hard. Over the course of the Eclipsa Trial story arc the Pines, Star, Marco and Eclipsa get on good terms (Ford has a paranoid time aiding the MHC because Eclipsa tried to hide her past with Bill from him and Dipper, but when she explains everything truthfully during the trial about the nature of her deal with Bill, he sympathizes with her and they become very good friends honestly) and the Monster Bash goes a little better than canon, but Bill has a few aces up his sleeve.

Planning for the Monster Bash would be when Mabel first arrives on Mewni. She immediately tries to hit on Marco (causing Star to pick him up, carry him a good distance away, walk back to Mabel, point at her, and say "No.") but otherwise does a very good job helping plan the party and makes a significant step towards improving herself by sympathizing with the plight of the monster population and feeling incredibly good about the work she does for the party. Her arc is still complicated from here, but the plan always was for this to be an unambiguously positive step forward for her which she explicitly is challenged on, thinks back to, and morally upholds later on.

Marco spends a long conversation in a monster temple hallway with Dipper telling him to be careful around Janna and not to let her mess with him, but she and Dipper end up hitting it off really well at the party over their shared interest in the occult, which Dipper has gotten a lot more expressive and confident talking about during his apprenticeship. In fact, they know each other from an internet forum for black magic practitioners: Janna's username is BitchWitch69 while Dipper's was AstralReader42. Janna is from there on out able to break into the Mystery Shack as easily as she does Marco's house but whenever anyone actually asks why she's there she actually has been invited by Dipper to test some magic. She also gets along with both Stan twins and Eclipsa. Mabel is the one who sincerely finds Janna weird and unpleasant, which she and Marco relate over.

Anyway, while Star does more aggressively pursue monster relations here and does make peace with groups, a significant monster faction armed with human weapons joins the Lucitors when they invade the surface world in the aftermath of the Meteora disaster. While the heroes fight fiercely against him, the odds are simply impossibly weighted in Bill's favor: Mewni is devastated and weak after two back to back magic invasions and besides the Lucitors and the Monsters, Bill has one more division of elite troops created in the depths of the Underworld: Soulgem Warriors, gigantic and oddly feminine gemstone studded alchemical golems created through a blending of Underworld blood sacrifice magic and the Solarian Warrior project.

With the aid of these, Bill crushes all resistance, forces the heroes to retreat to Earth, and the Lucitors seize Mewni. The story then becomes about the characters forming a rag tag resistance effort on Earth, using portal insertions for targeted strikes against the new Lucitor Empire, which has enslaved the entire dimension and is working them to death to build a massive pyramid shaped magical conduit that will let the Lucitors break the dimensional lock Hekapoo placed on Mewni so they can conquer more dimensions (what Dave thinks it will do) and cleave the Nightmare Realm to all of reality (what it will actually do). Ironically, this ends up doing a lot for Mewman/Monsters relations as everyone is suffering beneath Bill's tyranny and camaraderie begins to develop when they have to fight against him together.

But for the course of that conflict, all the protagonists are on Earth, living in the Mystery Shack as it basically has to close its doors and become a full scale command center for an interdimensional war. The portal has to be used sparingly because Bill is obviously watching and scrying on earth even as he's trapped on Mewni, and using it too much gives him insight into how to build his dimension breaking pyramid. Hekapoo and Ford are essentially the mission control for small expeditions across the multiverse seeking weapons to use against Bill, eliminating the other Bill fragments so their power bases won't unite, and trying to cut Bill's access to other dimensional resources.

Lots of character cross-interaction happens in the downtime between these missions, naturally, and the structure of the missions gives lots of opportunities to see how different team compositions would work together and interact. Eclipsa gets along very well with the Stans, the MHC have plenty of goofy shenanigans trying to live like normal people in Gravity Falls where the townsfolk barely react to the guy with a diamond for a head and the vampire lady whose always on fire. Janna's somehow just living in Gravity Falls now, as she is wont to do, and Marco eventually finds out about his baby sister when his parents unexpectedly show up in Gravity Falls on vacation: The Diaz family opted to visit somewhere scenic and tranquil for Angie's pregnancy and were wildly misinformed about the town. They're honestly freaked out about the fact that Marco has basically become an inter-dimensional soldier in a war against Satan but don't blame Star for it, showing sympathy and understanding for the young princess having such brutal responsibilities thrust on her at this young and knowing their son well enough to understand that they can't stop him from supporting Star. They are sort of bit characters who don't really go on the portal missions or anything, but fight viciously to protect the children anytime Bill's agents reach Gravity Falls itself and their open acceptance of Star into their family is a foil to the rigid and demanding attitude Moon has towards her.

This war against Bill and the many forces of evil assembled by him and his fragments would have been the third act of this saga, the crossover aspects being incredibly wide now and featuring large amounts of dimension hopping, plan making and mystery solving action while most of the characters have reached the end of their development. Moon and the MHC are ultimately the ones who fail to learn from their experience the most, while Mabel has become a fully positive contributor to the team and is on good terms with and nicer to Dipper now, and it is during this war when she specifically begins to encounter and overcome temptations to her flaws with the lessons she finally learned over the last two arcs.

This is where the Steven Universe stuff enters the picture. The second most successful Bill fragment in the multiverse is one that found himself cast into a dimension where the Diamond Authority is locked in an intergalactic war of superiority against the Irken Empire from Invader Zim, with both tyrannical star nations serving as foils to each other. Both are aggressive, fascist empire populated by artificially bred and engineered citizen castes that relentlessly pollute and despoil the worlds they conquer for resources and are commanded by the physically largest members of the species. The Irkens are screaming, shouting lunatics who preach the glory of the tallest amid suicide lightspeed rams, from atop weapon studded invasion robots and in mass human wave tactic charges, while Gemkind is more cold, composed and orderly in their systematic eradication of all organic life but this is explicitly an evil vs evil war for control of the universe that the other inhabitants of the galaxy are just trying to survive. In terms of shout outs and references, Irkens most commonly get Dalek references while the Gems quote the Galactic Empire.

The Bill fragment became a scientific advisor to a highly ranked Gem officer in this reality and was able to use their advanced technology to contact the Bill on Mewni and rig up a limited dimensional portal connection that ended up severed when Hekapoo locked Mewni down, necessitating the pyramid. With Bill's knowledge, this Gem elite invented a way to quickly produce more Gems by cremating large amounts of organic matter inside pressurized industrial ovens to create what in the real world are known as cremation diamonds, that become perfectly aware and obedient Gems through the addition of Lucitor soul magic to fuse the souls of the incinerated into a functioning consciousness and programming into the otherwise inert stone. These are being used as quickly produced shock troopers to overcome the Irkens at the cost of the Diamond Authority becoming more brutal and aggressive towards neutral parties, intentionally conducting thorough exterminations of sapient planetary populations to fuel the furnaces in addition to breaking the planet itself apart, which suits Bill just fine. The Diamond Authority in this AU are unambiguously horrific space nazis that have exterminated trillions of sapient beings and that even the more monster-phobic Mewman characters find disgusting and loathsome.

This fragment is the second to last Bill piece the heroes overcome, and thanks to its manipulations and the growing power of the Bill on Mewni (who at this point has looted Hekapoo's forge and has the dimensional control pyramid almost complete) the majority of the hero cast is trapped in this dimension, separated into smaller parties and more or less forced to fight the entire Diamond Authority and a lot of Irkens while trying to reach Bill's laboratory on the Homeworld, where Ford can rig up a portal to take them back to Mewni for the final showdown.

This was pretty far ahead in the story so it wasn't sketched out in as much detail as the other stuff, so group composition was kinda vague, but these are some of the things I wanted for sure to happen:

-Eclipsa, Stan and one of the kids (probably Marco) end up in basically the beginning of A New Hope, portalling into a ship crewed by the Federation insects from Rick and Morty while it's being chased down and boarded by a Diamond Authority vessel, complete with a scene where Amethyst soldiers (sporting actual laser projectiles instead of exclusively melee weapons) burst through an airlock and overwhelm the ship's defenders in a running firefight before a cape wearing Jasper strides in to choke the captain to death.

-Ford and Dipper end up on an alien graveyard planet inhabited by an order of monks/cryogenic scientists that devote themselves to interring and caring for a galaxy's worth of dead and the many diverse rituals that alien cultures center around the deceased. The planet itself is on the edges of known space and is lightly inhabited by the living, so a small, elite survey team has been dispatched to capture the interred dead to make more cremation Gems, creating a cat and mouse game where Gem elite soldiers are hunting Dipper and Ford through catacombs while they try to use their combined scientific knowledge to make sense of the alien lifeforms.

-Mabel ends up on this dimensions version of Earth, where the Crystal Gems are still living in blissful ignorance of the war consuming reality above them. The events of the show's backstory happened pretty much exactly the same, but the Diamonds essentially shelved any further focus on Earth after Pink's "death" due to the war with the Irkens, content in knowing the Cluster will eventually blow the planet up. Mabel quite naturally falls in love with Steven, but unlike her previous crushes this is a more sincere infatuation with someone she's genuinely compatible with that has genuine potential to make both of them happy. However, the earth of SU is specifically meant to be a foil to Bill's Bubble: A relaxing, idyllic environment that doesn't quite make much sense but is full of fun, quirky singing friends that Mabel easily makes friends with. Ultimately though, Mabel shows her character growth by willingly leaving this behind to return to the stars and join the war against the Diamonds, not just to save her brother but everyone innocent they threaten, while the Crystal Gems remain on Earth and are unwilling to return to the fight.

-Much further down the line and having used the investigation practices she learned from Dipper to figure out the truth of Pink Diamond while she was on Earth, Mabel is in a position where she's staring down a Diamond Authority flagship commanded by Yellow Diamond, who is basically threatening to glass the planet she's standing on unless they give them the truth about their lost relative while Dipper is aboard their flagship. Using their sibling teamwork, Mabel essentially baits the Diamond into firing by saying something horrible about Pink/comparing the situation to how she lost her sibling for awhile but got them back, unlike you! that enrages them into ordering the bombardment, only for the ship to explode as a result of Dipper having sabotage the weapon structure so it backfires. This explicitly results in the Diamond in question and the entire crew of the battleship being killed, because the Pines family doesn't fuck around and from the beginning have no qualms about violently fighting or killing soldiers of the Authority. Like the idea of talking about this literally never occurs to them. Mabel then goes around with big, thick bedazzled boots and gleefully stomps on all the falling gemstones that didn't burn up on reentry.

-Blue Diamond perishes aboard her human zoo as a result of a fungus bioweapon being deployed by the Neutral League of regular species caught between this galactic war. Ford, despite having initial misgivings about developing a bioweapon, eventually help them develop an extremely durable strain of nearly invisible fungal spores that dissolve Gemstones into a liquid slurry they absorb for subsistence in order to grow and bloom again, literally dissolving and wasting away all Gems they come in contact with. Possibly a Ford and Rick collaboration project.

-Without the means to assemble an actual army of fleet capable of storming the Homeworld to reach Bill's lab, the reunited protagonist team smuggle large amounts of the fungus aboard a cargo freighter and blow it up in high orbit, causing the fungus plague to break out and ravage the capital planet. White Diamond is powerful enough to survive and even eradicate the fungus but she is blasted to dust after a protracted battle between her and a wand bearing Eclipsa, leveling huge swathes of buildings in a titanic clash of monarchs.

-The Gem officer who made the deal with Bill and has been his primary tool for moving Diamond Authority troops against the protagonists is unceremoniously shot by an evacuating underling that they had regularly abused while grandiosely proclaiming that she will now rule the galaxy with the Diamonds dead, having never met any of our leads face to face. The Pines and the Butterflies reach the laboratory and prepare to launch a final attack on Bill. When they return to Mewni however, it's gotten really bad.

-The nightmare realm has begun to fuse with Mewni, darkness, evil and danger sprouting from the soil like a slow motions version of Weirdmaggedon, but this time the Pines family and their allies stand together against it from the start. A massive battle of might, magic and the mind rages across a Lovecraftian dimension of pure suffering, where the very air itself shapes to Bill's malevolent will and the soil groans underfoot with the death rattles of broken and discarded slaves.

-Bill has been using the magic knowledge and legacy accumulated by the Butterfly family and the Lucitors to try and replace the aspects of himself the team destroyed and reach full power, turning himself into a horrific JRPG final boss for the final battle against everyone. ALL of the warriors come in for this one, including some unexpected reinforcements as the barriers between dimensions get weaker and weaker. The Pines occupy Bill's attention directly, the Butterflies plunge into the Nightmare Realm to destroy his source of power, while everyone else they've rallied together fight his legion of abominations outside the pyramid conductor.

-The Pines (Pacifica and Soos standing proudly alongside them) proudly proclaim their love and bonds together as a family and defeat all of Bill's tricks, including his last ditch effort to pry them apart by preying on the original division between Dipper and Mabel to no effect, showing how they've matured and are on healthy terms now.

-In a scene very closely based on The Death of Magic, the Butterflies gather the strength of their ancestors and destroy the Nightmare Realm from within, poisoning it from the inside and destroying Bill completely. Mewni has been too thoroughly infected by the realm at this point however, and after everything spread by Bill's corruption is peeled back from the landscape and destroyed with the receding Nightmare Realm, the fragments of landscape and people left behind collapse, guided by the hearts of Star and Marco back to Earth, cleaving what is left of Mewni to Earth.

-The dimensions of Earth and Mewni are now cleaved together, but with Bill permanently destroyed a new, peaceful age can dawn. The Pines and the Butterflies become leading figures for peace and understanding in this new world, the magic expertise and knowledge both groups possess proving vital for harmonizing the displaced Mewman survivors and explaining to the world of Earth what magic is and how it has always been there. In this AU, the connecting point between Earth and the Realm of Magic sat in Gravity Falls. Everyone's personal relationships are sorted out with each other, Moon accepts that she and her people live in a new world that needs to be run by ideas, all the couples eventually get married and they all live happily ever after in a wonderful world of magic and science, ushering in together an unprecedented golden age of scientific progress, human peace and dimensional discovery.

Thank you again to everyone who has supported my writing here on . I sincerely hope that this Word of God, post-cancellation lore dump provides some sense of closure to anyone who was left hanging by my story and made for an entertaining read. Stay safe out there, and take care of yourself and those you love.