The Greatest Game - planning for a fic

This is mostly notes, ruminations and bit of planning of "The Greatest Game" fic I am trying to write, based off earlier idea outlined in Evil League Of Evil blog post I wrote some time ago. It's chock-full of SPOILERS, so you may not want to read ahead. Just a fair warning.
By the way, if you're interested in beta-ing and giving feedback on the half-written stuff I already have - PM or comment here, because it's the second thing I'll ever have written and I am in desperate need of any help I can get.
Anyway, as the story progresses, I'll edit and re-edit this post, to reflect progress, as well as to add new thoughts I've had.

***

First chapter is meant to close out the events of the Equestria Girls. We establish that Sunset has fallen and expects retaliation and counter-bullying to start soon and that no one really remembers what exactly has happened during the Fall Formal (which is what I will use to be the canon for this story, because otherwise the attitude towards magic in this verse makes zero sense).
We further show existence of Gilda in this continuity and show that she is Shimmer's henchgirl and muscle, as well as her competitiveness with Rainbow Dash. Olso, in this continuity RD does karate, as well as being captain of every sports team ever. Because IMHO that makes sense.
The chapter closes by showing Sunset's relationship with Celestia and how she got into CHS, which I think is a pretty well written scene. This provides closure to the Fall Formal events and a transition towards chapter two.

The dialogue scene I have currently sucks ponyballs. The references to the Rainbow Rocks dialogue are ok, but it needs a lot more RareSun chemistry if I am to make this ship work on a timescale I need, and there is no decent ending to it. It needs a complete rewrite, hopefully one that'd add some tension as well.
While writing out thoughts on the composition and politics of the CHS, I've thought of the idea that during the dialogue scene, Susnet tells the girls that they don't know how horrible she was, and tells Pinkie to tell the girls her secret, releasing her from the Pinkie Promise, and then runs away, unable to face the girls when they, as she thinks, will immediately abandon her, and goes to face Celestia.
Rainbow Dash catches up to her, and tries to reaffirm that they will stick to Sunset as long as she tries to reform, but sunset just gets annoyed at her stubborness, which provokes Gilda to intervene, as per already written part.
I think this requires that I rewrite the Celestia dialogue a bit, just make the tone less repentant and more resigned, which is a pity, since I really liked that scene and I'm not sure I won't ruin it, but I think I can do with just the most minor and cosmetic of changes.
Then in the next chapter, post-detention Rarity can confront Sunset, and get her to tell the story herself - how she has brutaly beaten up Derpy over her trying to complain to Celestia when Sunset screwed her out of her society's funding. It would be pretty gut-wrenching thing, if I can swing that, and then that prompts Sunset to break down yet again, and this leads to Rarity still accepting her, on the basis that Sunset will have to apologize and make it up to Derpy, and gives Susnet her make up kit, so that she can fix up her make up and generally make her feel better.
This makes the make-up kit a much more prominent symbol of acceptance and friendship than what I have now.

***

The second chapter starts with a little morbid joke, a decent, if mostly pointless scene that I had in my mind for some time. It furthers Rarity/Sunset chemistry, again, since I'm on a short time frame here. Does a bit of cultural differences discussion that I do enjoy.
Then I have a little "Sunset meets Filthy Rich and Spoiled Rich" scene. This further establishes her relationships with the other characters that may be important further in the story, and adds to the mystery of the connection of Tiara and Sunset, through showing that Spoiled hates Sunset, while Filthy "Fil" Rich likes her. There's also the exchange that shows that Sunset tutors Tiara and interns in Barnyard Bargains, which partially explains how she can afford stuff in this world. I like this bit, because for me it is considered well-written, but I'm not entirely sure as how to make it fit with pacing... maybe a few barbs from Spoiled would make it better, to wind up Sunset a bit before the next scene.

Then I cut to the Judgement scene.
This scene establishes The Cabal - the informal rulers of the school. At the moment, what I have is:
*Diamond Tiara, who is the editor of the school paper (as per Poniville Confidential). She's the media outlet of the group, shaping public opinion and making trends.
*Silver Spoon, who is her secretary/personal assistant/organizer type as well as the maintainer of the spy/blackmail gathering network in the school. She's the information gatherer and organizer for the group.
*Gilda, who is the muscle, as stated above. She is second only to Rainbow Dash in ass-kicking department (pre-magic) and has a big pull among bullies and delinquents of the CHS (e.g. Diamond Dogs).
I'd like to add someone else, but I have trouble coming up with any names and/or positions. Maybe Trixie? I don't think that would work, but she is good as an alternative to Pinkie, maybe.
Sunset still runs the whole shebang - she is the one who "saved Tiara's life" (which will be shown later), she has Gilda's strong loyalty due to pre-CHS events (again, discussed or shown as a flashback later) and Silver Spoon goes where Tiara does anyway.
This time however things are different - she done goofed (for the first time in Cabal's memories), her behavior during EQG events was near-psychotic and she is somehow responsible for blowing up the school. So they are concerned for her, and want to be sure she is still fit to lead. This is, by design at least, a very cutthroat organization so Sunset half-expects them to drop her under the bus the second she stops being an asset and becomes a liability - something that is very likely after the events of Fall Formal.
I think I'll just have them piling accusations and demands for explanation unto Sunset until she explodes, reverting back to her old QBFH form and reminding them that she still holds them by the unmentionables and that she is still the meanest, smartest, most horrible thing around that got them where they are now. I think it sorta works even with the amicable ending I wrote before that.
There's a mention of previous vicious/bullying things that Sunset did, which I may flesh out later. Or not.

Then it's next day, or rather morning. Sunset's summoned to meet the girls in the morning to greet a new arrival.
That would be Fleur, who arrives in her boyfriend's uber-car, and the reader finds out that she is Rarity's friend from Prance, who has moved to Equestria to be with her boyfriend, Blueblood who is a technically an Earl of Equestria. (He is an Earl, because his father is a Prince.
I generally take equestrian title of Prince/Princess to be equivalent of Italian/Russian prince - a generic high noble rather than royal scion, and therefore, per British peerage system as I understand it, the eldest son of a Prince would hold one of his father's courtesy titles, which, in this case would be "Earl of Hollow Shades")
Rarity runs up to them, with other girls, sans Susnet following slowly behind. Sunset, being herself, eavesdrops on the conversation through lip-reading. Rarity does the standard pas de deux, gets introduced to Blueblood. Blueblood is introduced in an exemplified manner as to denote his douche-ness (I'm thinking of some phrase that on a surface looks nice, but is really, really objectifying and misogyinst once you think about it), show his interest in Rarity as well, which establishes the grounds for further conflict.
Girls come in and join the conversation, Rainbow, Pinkie and AJ embarrassing Rarity with their directness and uncouth ways, and Sunset goes to salvage the situation a bit, distracting everyone, greeting them and offering a tour as a Student Body President (which she still is, since it's distinct from Princess (as stated in EQG, being a Fall Formal Princess comes with no executive powers whatsoever)), which Blueblood decides to join, all the better to ogle Rarity and just because he generally has little to do with his time.
The interaction show glints of cruel alpha queen bitch that Fleur will be later, e.g. through her instantly noticing Sunset's portraits and the lack of latest victory portrait and twisting the knife in the wound by asking some "innocent" but sharp questions that also betray her interest in taking the top rung in the local food chain.
Sunset gambles on the Law of Dimensional Symmetry** to distract Fleur and Blueblood from ripping into her past and/or bothering Rariry she impulsively and desperately throws in few questions and fact that she would not be supposed to know about Blueblood and his Prince Father - things she knows, because, in my head canon (which is completely wrong***) time-line, Sunset knew pony!Blueblood, since she was about the same age as they were growing up in Canterlot
That makes her seem like she has an in with the Canterlot Nobility, to scare Fleur a bit of messing with her, cow Blueblood a tad, intrigue her friends (and in fact this is sort of semi-flirtatious with Rarity, even if it's too early for Sunset to figure it out herself).
That will be a hook for a later discussion in the Sugarcube Corner between her and the girls where I can throw in things like her having held Celestia's courtesy title of Marchessa of Winsome Falls while she was Princesses' protege, and technically outranked Blueblood.

***
SCENES WRITTEN AHEAD:

*An intermission-style short chapter Sunset thinks about her day and/or has symbolic nightmare, wherein we establish that while she did think of Tiara/Gilda and others as minions or at best as business venture minor partners, she may start to consider them to be friends. Some RareSun thing is to be expanded again, not by much, but just keep pushing it bit by bit.
I got the nightmare, more-or-less. I also need a little preamble, to explore the friendship/Rarity thing.

*The scene where Sunset explains to her new friends how budgeting, extortion and embezzlement scheme worked under QBFH!Sunset, and how she has to un-tangle the byzantine web of inter-dependencies, lies, bribery and double accounting to get it straight... and whether it can actually be done without setting up a bloody revolution.

***
THINGS TO WRITE IN THIS ARC:
After that things get a bit fuzzier. In my mind, there will be a few chapters of Sunset essentially being bullied as Fleur takes control of the school the exact same way Sunset did.

*Previously-corrupt clique leaders start to test out Sunset, to see whether she can actually support the system she used to have, as well as coming up with grievances regarding how their own minions are looking to get on the Friendship-and-love wagon that Twilight started and rocking the wagon. Lighning Dust tries to bully Susnet a bit, and maybe gets rebuked by one of the Mane cast, maybe Rarity even or Rarity and RD. Spot reminds her that Diamond Dogs are only as loyal as long as they get their kickback from nerds and ecos, Sandalwood tries to say that he believes he no longer needs SUnset to protect "His people"... something to that tune, to show Sunset under stress, all the while she gets shunned and minorily irritated by the revenge-bullying by the general populace.
*I think maybe a scene where Sunset's blackmail information on Lyra/Bon-Bon relationship is either discovered independently by Fleur or even supplied by Sunset to Fleur in order to let Diamond Tiara infiltrate Fleur's inner circle, and to neutralize it, Sunset has to force them out of the closet.
I would, in vein of making EQG!Equestria a perfect, or at least utopic, country (as outlined in the next blog post), assume that generally there is no sexual orientation-based discrimination in Equestria, and closeted relationships are in fact highly unusual. This will be due to Bon-Bon's being bullied over it previously and having a trauma regarding it, which is why she is terrified of anyone knowing she is in love with Lyra.
Maybe even build up on it, and make it so that she not only was bullied, but maybe did something horrible because of this, when the bullies pushed her too far, and then she, because she was/is a minor got to move and change her name as sort of victims/witnesses protection programme. That could have further repercussions in the Equestrian adventure arc.
*There really should be at least one scene of Rarity saving Sunset in some measurable way. Otherwise, with what I have in mind, she gets delegated too much to Damsel In Distress role, which is a horrible misuse of the character.
*The scene where Sunset tells the girls of how she had Derpy seriously beaten up when she tried to complain about her society's funding being taken by Sunset. That should really show how fucked up Sunset was, and there would be some sort of scene to make up for that.... in as much as you can actually come back from the Moral Event Horizon of beating up Derpy.
*Somebody steals Sunset's journal, even going as far as reading aloud some passages. The whole referring to Celestia as "Princess" leads them to think that Sunset had a crush on Celestia, which is embarrassing as heck, and everything else (mentions of dragons and griffins etc) makes people think she is a weird LARPer, which is sort of socially damaging. This ends up with Sunset regaining her journal and writing a long overdue "I'm sorry" letter to Celestia, with the letter being a separate Intermission-type short chapter.
I think I can and should involve Trixie here. She looks like she could be into O&O stuff, and that (as well as mutual love of magic and being socially accepted) would allow her and Trixie to bond, and get Trixie to be, if temporary an Element of Laughter in Sunset alternate setup.
How that would work post-Rainbow Rocks I am not entirely sure, but I think, given the time before I'll need that in Friendship Games, that could be workable. Maybe actually make Sunset play O&O once her life becomes little less crazy****?
Some scene to the tune of Trixie actually calling in the favor she owes Sunset to press her into playing, and then she kinda likes it and it becomes a regular thing, until Trixie is gone due to events of RR.

But generally she gets the whole being bullied experience in dozens of humiliations small and large, as her former minions seem to betray her as she tries an insane balancing act of trying to untangle her own system without blowing it up. Diamond Tiara publishing several horrible articles like "Sunset Shimmer is a monster we always knew she was!" and some stuff on her background - that she is an orphan, that she is in school as a charity case and etc, stuff that can really damage girl's reputation in a rich-neighborhood school. This increases tension, makes Sunset suffer and try to soften the blows but also opens up her background a bit.
Meanwhile Gilda not only ignores Sunset being bullied, but almost seems to provoke that, forcing Sunset to rely on herself and occasional help by Rainbow Dash and Applejack to get out of more physical situation. Probably goes to Fleur's sort-of-kind-off bodyguard cadre of Diamond Dogs as well.
For a while, Rarity and Mane Six don't exactly notice this sort of stuff - most of Mane Six are not exactly socially acute (as established by the main series), and Fleur takes some extra effort to try to look nice near Rarity, probably to use her for fashion stuff.

Then stakes are raised one more time when Blueblood starts to make his (unwelcome) moves on Rarity, and that is brought to Fleur's attention, so Rarity also becomes a center of Fleurs terror campaign. Her dresses get vandalized, her social appearances ignored and etc. Not to the level of Sunset, who is generally despised by the school, but then Rarity is made of somewhat less stern stuff, so that's sufficient. And all the while Blueblood keeps essentially stalking/molesting her.

*The penultimate scene of the arc would happen when Blueblood and his cronies corner Rarity and Sunset (who probably preempted them and tries to warn/protect Rarirty) in her fashion club room, and essentially attempts to rape her. This prompts Sunset to reach out for the RED inside her hulk out and start biting and clawing hench-guys eyes out, while her shoulder gets dislocated.
Then Gilda shows that she was essentially working undercover, and knocks out Blueblood, as he almost chokes Sunset.
Gilda resets Sunset's shoulder, and there is a short tender scene where Rarity makes up Sunset to cover the bruises and cuts she has, so that the final part of the plan can be reenacted.

Then comes... well, something. I've no idea, but in essence it is Sunset's long-con counter-play, wherein she destroys (socially speaking) Fleur, humiliating and outing her as a total flankhole so hard she has to transfer to Crystal High, at the same time earning herself a respite from everyone hating her (either part-earning forgiveness or by showing their hypocrisy in how they essentially changed one ass of a ruler for another, despite all that Twilight has done for the school).
There may or may not be a need for some school event as a background. Since Rainbow Rocks ostensibly happens no more than a month, two at most post EQG, that means it's too early for Winter Ball, so, perhaps some sort of raffle or something like that.

Thus the first arc ends as whatever the event proceeds, and finer points of Sunset's plan are discussed and shown as flashbacks.
After that Fleur shall leave CHS for Crystal Prep, to reappear in the Friendship Games.

*I also think I want the pointless-but-fun scene where Sunset goes out drinking/clubbing something to the tune of S.J. Tucker Firebird's Child.
Either she'd get blind drunk Buffy-and-Faith style, and rely on Gilda to drag her out (and maybe kick some douche's ass along the way), or maybe it will be implied to be a regular girls night out to which she may drag Pinkie, Rarity and Rainbow and hijinks and some Equestria vs Girls differences discussion will ensue.
Maybe as celebratory scene before starting a RR arc?

__________
FOOTNOTES:
**I will generally use, and later - explicitly mention that Law of Dimensional Symmetry essentially claims that you can only (or at least most easily) open portals between the places that are symbolically similar. That's why the CHS is so similar to Equestria - if it weren't there probably would not be a portal at all.
Sunset will use that to her advantage, because information that's really hard to get in one world may be readily available in the other, like for example she uses the tale of Two Sisters and Mare in The Moon to figure out Principal Luna's criminal past and blackmail her with it, or to use her knowlege of pony!Blueblood against the human!Bluebloood, or, much later, find Sweetie Drops despite her changin the name, just by knowing EQG!Bon-Bon.

***Yeah, despite my long argument with MLai, I kinda have to admit that the idea that Equestrian time is faster than EQG time does not work. Were Twilight in her first trip to spend more than a week in alternate universe when her friends think that portal closes in three days, they would worry themselves insane and that would have been mentioned.
I am still keeping my timeline, though, it's just too convenient not to, and I invested too much in it.
It's AU fic anyway, so bite it.

****I really like this idea. There would be a scene where Sunset is kidnapped, with a cloth sack on her head and everything, and she is scared-but-defiant. In the dark cellar she is met by cloaked figures, and in a struggle she beats the cloak out of one of them to discover it's Flash. She says something to the tune that she always knew his Good Guy facade was a mask and that one of theese days he'd snap and start murdering people. Then light come on, and it's sort-of prank, and she was supposed to be warned, except that Trixie forgot to do it. And it's a traditional ceremony to get people into their O&O game party.
Anyway, others turn out to be Trixie (the TN human sorceress), Flash (the elven paladin), Vinyl Scratch (the CG human barbarian) and Crimson Napalm (the DM), and they swear her to complete secrecy regarding the club activity, cause it is sort-of-nerdy and they'd be shunned upon by their respective cliques.
Sunset then joins as a (CG halfling rogue).
There may be a humorous intermission chapter about their session somewhere down the line.
_____________

EVEN FURTHER
I've at least four arcs (each to the tune of 10-12 chapters) planned.
The first is the Conquering the School arc, as outline above.

The second arc would be Nightmare Rarity arc.
Here Rarity suffers from trauma inflicted by a rape attempt. There will be a lot of romance development, with some sort of action in background (related to drug pushing), then Sunset will make a move on Rarity, which the latter will deny, as she is straight, saying that she really, really wanted to love Sunset as she is brave and strong and nice and was technically a noble which is a bonus. But cannot, because she simply does not think of girls that way, at which they resolve to (at least verbally) to stay friends, but actually sort of start avoiding each other, because it's awkward.
There is some character development and maybe minor school shenaningans. Also I'm thinking of a scene where Sunset tries to get Diamond to be friends with CMC under the guise of asking her to infiltrate the CMCs to gather information on their big sisters.
There'd be a big scene where Sunset gets her red side into a twist, not wanting to accept rejection, and figures out that there ought to be something she can do - a spell, a potion a poison.... but then ultimately accepts things as they are.
They will stay apart for a bit, until Sunset notices Rarity acting strangely peppy, and happy and working in weird bouts of over-productivity (Inspiration-Manifestation style), followed by periods of downs where she barely attends school. She tries to investigate and figure out what is going on, which provokes Rarity, high as a kite on something, makes advances on Sunset.
Sunset shuts it down (barely) by pushing Rarity into cold shower. They talk a bit, and she figures out that Rarity is using the drug, familiar to Sunset over her Luna case.
They try to stage an intervention with the Mane Six, but Rarity just does not come, and in fact disappears completely both from the school and her house.
It takes some time, but Sunset hunts down the drug distributors (in a scene with Hoops and Dumbbell, Gilda and an abundant use of a baseball bat), assembles her team, which I want to be her alternate Elements of Harmony (Gilda as Honesty, Sunset as Magic, Diamond as Generosity, Silver as Loyalty and Trixie as Laughter, the final being Rarity as Kindness) which, at this moment makes no sense...
I mean Gilda makes sense as the muscle, Sunset is also obvious, Diamond and Silver may tag along unasked secretly, but Trixie... maybe for her skill with lock-picks and locks as part of her stage-magic ability. I'd have to see how it goes.
While they try to dismantle the organisation one way or the other, perhaps by stealing the ledgers and taking evidence, or something like that, they get captured and get to demonstrate their respective Elements. Gilda tells Susnet something brutally honest that motivates her to pick herself up and get back into the fight when she despairs, Trixie stays jubilant and self-assured in the darkest of times, Diamond gives up her tiara for something important (perhaps breaking it to get Trixie a lock-pick to escape), Silver stays loyal to the group despite...some sort of conflict. Maybe her family would be implicated somehow? And Sunset coordinates and leads them, providing the requisite spark of magic to make it all complete.
This is done in a sort of subtle way, so that it has "was it really magic" sort of feel, to provide a coincidental sort of edge.
In the end Rarity gets saved from the Nightmare Gang, she gets an intervention and agrees to a detox.

The Rainbow Rocks arc.
This will be a shorter arc, three to five chapters at most, which would be re-telling of the Dazzling Illusions fic I wrote from Sunset's perspective. The focus would be on expanding the relationship between Trixie and Sunset, Rarity and Sunset and Twilight and Sunset, the latter being about struggling with the feelings of jealousy towards Twilight Princess-hood, still being in Celestia's good grace and generally being much better at magic.
There'd be a scene where I can finally use Sunset-Zecora counseling sessions, wherein she will be made to acknowlege that she is indeed still jealous of Twilight, and still in a big way evaluates her life on what would others want of her rather than what she wants for herself.
Her attempts to upstage Twilight, exacerbated by siren's magic, strain her relationship with Rarity and sabotage the Rainbooms, whereas Twilight is not so sure that SUnset changed her ways, since she is behaving like a douchebag and still runs CHS, even if in a much cleaner manner. It takes both Elements of Honesty to make both of them overcome their hostilities, Sunset to apologize and peace to be restored, just in the nick of time to rush out and defeat the Sirens... when all their magic is suddenly ripped out of them by Trixie's transformation into a Siren, and they black out.
They find out what has happened, more-or-less from the confused crowd, and again try to regain their magics, afraid of Sirens coming for the second attempt at world domination, as well as try to find Trixie, until the sirens summon them to parlay as per "Negotiations" chapter I already wrote, in which it is explained that Sirens also have almost no magic, Dagi and Trixie have this twisted magical co-dependency thing that is perversion of everything good that is love and are leaving for Crystal Prep because Trixie is very weak after not being able to hold in her magic and constantly needing to feed on energy, while Aria and Sonata stay in CHS as, essentially, hostages and ambassadors of Sirens.
Twilight has to go back to Equestria, and she and Sunset decide to be pen-pals, which would be referenced few times further on.

The Filler arc.
Ostensibly, EQG is end of October, RR is soon after (end of November, maybe?). FG, in my headcanon, take part just before Spring break, making it mid-spring, so there is a pretty big timeskip, filled with Sunset's winter internship (may be worth a mini-filler-arc, if I think of something fun to do there), and a general reestablishment of the baseline.
Rarity recovers slowly, Sunity initial awkwardness is gone and they are back to being friends, while Shimmer keeps pining for her, but mostly keeping it to herself, perhaps confiding in Rainbow Dash.
With the come of the spring there is dating abounds, with RD hooking up with Bulk Biceps and Flutters with Big Mac, and even Diamond Tiara comes up to Sunset for some dating advice which is played for general hilarity.
Sunset deals with starting to run out of cash, and trying to figure out what to do to gain some, since bullying and blackmail no longer are viable options, nor is stealing from Equestria or cooking the books for Flim&Flam scams.
Some minor adventures happen, to involve various combinations of Sunset elements, Human Five and Sirens of CHS (Aria and Sonata), something to the tune of the first Buffy seasons, where generic high-school problems get exacerbated by influx of magic through the portal.
Girls slowly regain their magic back, and start ponying up again, albeit weaker and uncontrollably, only in times of great need.
Likewise, the red thoughts return again, and Sunsets struggles with not relying on the power and rush that comes with drawing upon the red and not reverting to being a QBFH.
This should be five to ten chapters long, depending on whether any good ideas pop up.
Maybe even a short actual Buffy cameo, wherein she discusses with Giles-expy an increased occurrence of supernatural phenomena in Canterlot City, and note that it's due to some opposite of Hellmouth that leads to a positive plane, with Buffy-expy sulking that she wants to be a Slayer in a town where invasions happen from a place of ponies and sunshine, rather then tentacly horrors of actual Hellmouth.
Obviously no names would be drop and it would just be a weird side-episode of a blink-and-you-missed-it variety to maintain plausible deniability of a crossover.

The Our School arc
Trixie appears back, as well as Adagio, telling that some stuff is happening at the Crystal Prep that is seriously scaring them.
Apparently there is a new group in the school, that I will be totally ripping off that communist-christian thing they did in one of the Misfits finals, that somehow through organization, prayer and camaraderie and discipline become not only completely immune, but entirely antithetical to siren magic. THey keep growing in scope, very quickly assimilating new members, and are lead by charismatic and smart (you guessed it) Starlight Glimmer.
There'd be a fun exploration how in EQG-verse Christianity sort of never really caught on, and is more of a weird sect that very little people actually know anything about, and maybe a bit of trying to describe it from outside in a non-derogatory but sort of more objective view, and maybe have Starlight Glimmer actually try to convert some of the cast. I can very much see Fluttershy being interested, maybe Rarity, who is still struggling with stuff, and definitely Sunset who notices that Starlight presence seems to quiet down the red.
Adagio an Trixie are pretty much ready to bolt the Crystal Prep, but Sunset wants to investigate, grabbing a couple of friends, under the guise of inter-school commission for liaising on the upcoming Friendship Games they enter Crystal Prep, and maybe even try to infiltrate the Glimmers organizations.
At first it seems entirely benevolent, but sooner or later, the more sinister font appears - the deeper one is integrated into the organizations, the more it seems to entirely subsume their personality, turning them into sort of perfect drone comrades - polite, helpful, organized, smart but really lacking any distinguishing features. They even find Starlight, who has started the process (perhaps with some parts of stolen somehow siren magics, or some equestrian artifact or something to that tune) who is herself getting scared of her organization.
Through subterfuge, adventure and something-or-other they manage to destroy the whatever McGuffin made the thing possible and with some effort manage to break the whole organization apart, restoring the unfortunately normal mutual hatred of Crystal Prep.

The Friendship Games arc.
This would be in the same vein as the show, although I'd change up the events list a bit, because it made absolutely zero sense in the original.
Archery? Motorcycle racing? That's just weird for a school Academic Decathlon. Not even sure if it's even legal, since they're minors, and cant' even drive without adults.
Anyhow, the arc would be centered about teams spying and counter-spying, trying to sabotage each other and figuring out best match-ups.
The second plot would be Twilight trying to re-make Starlight's organization. The idea here is that through Starlight, Twilight, for the first time in her life actually made some friends... well, not exactly actual friends, but at least some camaraderie, wherein she was valued, not-bullied and appreciated, while allowing her to help in tutoring those less academically able than her. Since Starlight's organization fell apart in the previous arc, and previous members tend to avoid each other due to unpleasant memories of being swallowed in a psychic common consciousness, she is back to being a lone despised nerd, and she is willing to do _anything_ to get it all back.
Which the weird CHS-centered radiation of residual friendship just may be able to be enough to do it! (cue evil laugh). This also gives Twi vs Sunset rivalry a very personal feel, as SciTwi has every reason to hate Susnet with a fiery passion.
The Human Five try to befriend the Sci-Twi, bit she still hates them over the Starlight thing and thinks it is a ploy, even going as far as to pretend to be their friend to steal their magics into her weird device thing.
As to ACADECA:
The first stage would be a series of athletic events, featuring Greko-Roman wrestling (showcasing Big Mac as The American Experiment), fencing (wherein I have this nifty scene where Rarity is shown to be a good fencer, goes against Fleur despite that not being her match-up, and sets her up to drag off her mask and really whack Fleur across the face with her sabre to leave a permanent mark, as revenge for the events of the first arc), and martial arts wherein Rainbow Dash shows off, while Gilda is jealous and annoyed to a moderate comedic effect.
The thing ends probably in a tie (Big Mac wins, Rarity loses due to putting her personal grievance first and actually breaking the rules and being DQ-ed and RD gets a draw and a promise of rematch from Sweet and Sour)
Somewhere at that point I thought of that little scene to have Trixie showing magic tricks to CHS juniors and draining their adoration for sustenance, when Sunset sees her, and they talk a bit.
Trixie tells Sunset that she misses her family and friends terribly, especially Fuchisa and Lavender who are still afraid of her post RR-events when she mindraped them. She likes Adagio (and she loves Adagio) and she is feeling better, and Adagio is teaching her a lot about showmanship, but she really wishes to finally get better and return to CHS. Sunset invites her back to their regular O&O games, post FG, and Trixie accepts.
The second event goes as in the movie, with events on normal academic subjects:
Chem, English (spelling bee), Home Ecs, Industrial Arts, Languages or Art and finally Mathematics.
The third event would be ... I actually have no idea, what else is there in a school. Something emphasizing teamwork and coordination. Really want to involve Rainbow Dash/Bulk Biceps pairing in here. I'll have to look in Robert Asprins "Phule's Company", there was something similar.
This is where CHS, who before struggled to not get behind to far start to seem to get the advantage, when Twilight does her "unleash her magic" thing, assuming that if she does it in a way that lets CP win the FG, it will be more acceptable and more would willingly join the friendship gestalt. It does not...exactly work, and the joined scream of dozens being midnraped by twisted mock-friendship magic starts ripping the reality apart.
Sunset is sorely tempted to go red again, drawing out her own magics and going full-demon (something she knows she can do, much like girls could pony up), but finally defeats the temptation, and instead tries to talk Midnight Sparkle down. She explains that the mindcontrol thing is not real friendship, and that real friends tell you the truth even when it hurts, they help you even when you don't ask for it, loyal not because you force them, that they make you laugh and believe in yourself, that they are kind and gentle to each other, which prompts giant Friendship Nuke, joining the Sunset!Elements, transforming Sunset and generally fixing everything in a classic Saturday Morning Cartoon sort of fashion.
In the aftermath they talk to Twilight, who agrees to move to CHS to be with the Human Five and try the whole friendship (the real one) thing, and to work with Sunset on electronics/magic combination.
And then suddenly Rarity comes up to Sunset and kisses her fiercely on the lips, which is then explained that she did like Sunset always, but could like her like her due to being straight, but since they joined up in the Friendship Voltron, it no longer matters, because Rarity now can see not Sunset's physical appearance but her very soul, and it does no longer matter to her whether she is a she, a he or even a pony, she can truly love her and be in love, and so a 100k word romantic fic is concluded by a kiss. Or at least a long make-outs session.

The Equestria arc.
This is the big one, the one I really, really, really want to write.
Post Friendship Games there are finals (need to check if yanks do have finals in penultimate year like brits), and then the long-awaited, much needed summer vacation.
The Sunity romance is well-developed and in full bloom at that moment, Sunset Shimmer feels that she is ready to return back to Equestria, if for a while, and wants Rarity to meet her parents.
She selects an auspicious time, when Twilight and the Elements leave for the Gala so that she wouldn't actually have to face them or Princess Celestia, and uses Trixie's siren magic kept in one of her stashed Equestrian Gems, some of Sci-Twi's schematics and her own electronics and magics proficiency to McGuiver a portal-opener of her own, and goes through, taking Rarity with her, with intention of being there a few days, having a romantic date, dinner with her parents and going back before Twilight returns and anyone is any wiser.
They travel to Fillydelphia, where they stay for the night, before ascending to Cloudsdale the next day for a dinner.
In the morning Sunset earns some bits by storytelling and illusions performance. She tells a story of a brave little bird confronting the King of The Dragons who has been threatening and robbing the coast of Equestria to increase his horde, fighting him to a draw, and who then through guile and subterfuge and maybe treachery steals his only egg, using it as a hostage and making him cease his attacks.
Rarity asks her about it, and she tells that that's what she did, in her final years of being Celestia's protege - she did a lot of that sort of magical troubleshooting, and that she's not proud of essentially foalnapping an unborn dragon, and did that because she was already letting the pressure to impress Celestia to push her to the dark side.
She also mention that egg is nigh-invulnerable, magic-resistant and that last she heard of it they were using it as a magical test in Celestia's School for Gifted Unicorns (hintedy-hint-hint).
They go to Cloudsdale, where Sunset cast her cloud-walking spell on Rarity, as well as few others to again earn some bits, and they go to the famous Cloud Nine Pegasus-style fancy restaurant. There's a dialogue, grape-feeding-while-lying-in-a-roman-sofa scene, maybe some kissing and horn exploration.
Anyway something ... horrible happens in Canterlot, where the guests of the Grand Galloping Gala, all four Princesses are captured and incapacitated, Sleeping-Beauty (from the Fable comics) style, with briars enveloping the Canterlot Castle, thereby putting Sunset's vacation on hiatus.
That would probably be a ploy of Chrysalis who got her hands on some of the Discord seeds and modified them for a use as weapons... or maybe Zebra alchemy. Or both. There's ample time to decide.
Sunset takes it upon herself to save Equestria from the impending invasion, for which she goes back to EQG!Verse and grabs her allies - Rainbow Dash and Gilda, Diamond and Silver (Trixie being indisposed and in Las Pegasus), as well as Principal Celestia, whom she intends to use as a figurehead and a rallying symbol, pretending that she is actually a Princess Celestia who managed to escape the trap.
SHe also finds and recruits back to service the best monster hunter in all of Equestria, even though she dissapeared without a trace some time long ago, by using the Law of Dimensional Symmetry*** that she changed her name to Bon-Bon.
What follows is a long war, with maneuvers, logistics and all sorts of stuff befit "Sword of Truth" series, as much as I despise that bit of literary crap.
In the end good guys win, the spell is broken, the Princesses are released, and Rainbow Dash resolves to stay in Equestria. Because here she can fly. And actually have a real job in which she is useful, rather than resorting to military or sports career.
There is a scene between her and Gilda, where Rainbow uses the fact that she saved griffonness' life to make her swear that she would protect Dash's friends as RD would herself, with her life if she has to.
The bittersweet goodbyes are said, Celestia and Sunset talk a bit, and Sunset re-expresses the fact that she is very sorry that the whole apprenticeship didn't work out, and that she does not look to be Celestia's student any more, and there is a semi-teasing semi-tender moment of Celestia totally mothering Sunset (as per Chengar Quordath's Dresden/MLP crossover) and they part more or less amicably. Maybe even a Cadance and Sunset talk, reaffirming that I use Freeport Venture version of Celestia and Sunset falling out, with Susnet hurting Cadance in jealous rage.

I also have the scene where post-EQ-arc SUnset returns and gives Trixie&Dagi combo crystals filled with Equestrian Magic, to feed Trixie.
Adagio uses her singing to crack them and drain the magic, ponying-up in process and then feeds Trixie in a rather explicit and sexual manner. It's not significant or anything, and I'm not sure where it fits, but it just sort of is in my head.

That's all I have for now.
That should be to the tune of 3 full arcs and two smaller ones, at 12 chapters at 3k words per chapter, a 150k fic. The idea is to write it in about a year.