Thoughts so far:

-Harvest?

-Oogie dynamics:

• Trickster's mother was a prostitute. She loved them, but was very hands-off in her parenting, partially to keep them from the nature of her job. This has the caveat of the three not really having much in the way of moral guidance, particularly because she taught them (out of necessity) how to pickpocket.
  
  • "Go play until I call for you/this is important, do it."
• One of her Johns made her cry. While the trio doesn't know in what capacity, they feel turnabout is fair play. Shock masterminded the whole thing with the expectation he'd get hurt, and wrangled her brothers into helping her because it'd be funny. They didn't expect the man to break his neck, or to be spirited away by the boogeyman for it.
• They were forced to forget their old lives as a form of control, but respond to them same style of hands-off parenting. They bring Oogie things to eat and perform occasional tasks; they otherwise do what they want.

-Carmilla and Lillith:

• Formal, polite, loyal to the Pumpkin King. They're identical twins, but different personality-wise. Like her namesake, Carmilla is a lesbian, while Lillith is bi.
• Carmilla is also the only person in town who can rival Shock as the top bitch. Where Shock is calculating, devious, and mischievous, Carmilla is cold and polite.
• Lillith is a bit stand-offish, but much kinder than her sister.

-Agatha is still the token straight. She doesn't like trouble, but if there's an opportunity for subtle vindictiveness, she'll take it. Of all the teens, she's probably the closest one to a sweetheart. She's also probably the most responsible one.

-Band:

• Lock formed The Devil's Pitchfork as an outlet. He's going through a rebellious teen phase, and this is one area he has complete control over, since he can't overpower Shock, and he's tired of being bossed around by her, since after Jack, she's the closest thing to a parental figure the trio have.
• Starting band: Lock (lead guitarist, secondary vocals), Shock (lead vocals), Barrel (drums), Carmilla (secondary vocals, synthesizer), Lillith (theremin), Harvest/Aod/? (xylophone).
• Shock and Carmilla butt heads over the lead position. Carmilla has technical singing training, and is better in many aspects, but Shock can shriek and screech in different ranges, which Lock needs for his band. Also, she's his sister and he has an incentive to keep the peace so his band can actually function.

-Misc Halloween Town:

• Harvest(?) and Behemoth are bros because of their pumpkin patch work.
• The main Halloween Town musicians are fine with the kids creating their own band, as they aren't trying to compete. Halloween Town overall is supportive one, because many of the kids are doing something creative between Halloween prep, and two, if Lock, Shock, and Barrel are occupied with practice, they aren't causing trouble elsewhere.

Twin ideas:

Lilith is generally the more reserved and elegant one, partially out of a need to live up to a self-imposed concept of what a well-bred vampiress should be, and partially as a result of having to hold Carmilla back when she gets a bit too… Carmilla. She is patient, long-suffering, and used to going along with what the strongest personality in the room wants, but if she does reach a point where she thinks that rebellion or vengeance is necessary or useful, she can come up with creative and concise plans toward that end. She tends to see Carmilla as slightly more impulsive and self-centered than she actually is, and when they switch places, tends to play Carmilla as being a few shades shy of thoughtless and a bit more entitled. Her personal tics and “tells” include biting her lip when she’s considering lying, placing her hands behind her back or clasped at her waist to enforce her posture while standing still, and her glances toward people other than the one she’s talking to.

Carmilla is generally the more hot-tempered and party/sporty one. She’s used to having to pull her sister along when Lilith gets caught up in studies or is hesitant to quickly come to a solid conclusion or active decision. She likes to dive into things feet-first, not entirely without looking where she’s going to land but prepared to improvise as she goes. Her schemes generally have more variables than Lilith’s, which she adjusts to as she thinks of them. She’s not self-important, but will not take rejection or criticism sitting down when she believes that she has rightfully earned something. She is stubborn, and once she decides to do something, there is no stopping her -- including herself (she took those singing lessons for a reason). She sees Lilith as slightly more withdrawn and status-concerned than she actually is, and when they switch places, tends to play Lilith as a few shades shy of compulsively orderly and a hair more stand-offish. Her personal tics and “tells” include making direct eye-contact just a little bit more than normal, occasionally running a hand through her hair as if to make sure it hasn’t fallen out of place, and rocking back from her toes to her heels when she wants to change subjects.

More misc stuff:

-Twin/triplet switch plot. Teach the twins how to be in-sync with each other.

-Lesbian shenanigans.

• On that note, I think Lillith and Lock should start out dating (gives a reason for the twins to be in the band, and why Lock puts up with Carmilla, since she and Shock being in the same room for longer than ten minutes are bound to give anyone a headache). This adds more of a double-whammy in terms of drama with our Mysterious Villain when they break up, as well as packs more punch when vengeful dating starts. It's also a slow burn that fits into Lillith's aforementioned rebellion because at that point, she'd be fresh from a break-up, and therefore less willing to tolerate her sister's usual antics.
• As previously discussed, Shock gets clued into why this is vengeance against Carmilla.

-I'm probably not going to actually write lyrics, but you know their songs have titles like, "Screams of Hell", "Siren Song" (thinking this is one written to showcase the twins' abilities and training, since sirens actually, y'know, sing beautifully), "Wake the Dead", and so on. Definitely at least one about banshees.

-They've totally covered this song at some point.

-Date night! Beautiful crypt, and the potential of being caught.

• Sets up more status quo, re: Lock and Lillith's relationship. They each get a taste of the other's life and live vicariously.
• Lock is totally a sub. Lillith likes having some control. They get mutual benefit from it.
• Drama seeds planted, re: both of them trying to keep their respective sisters in line.

-Mummy Boy's older brother is Sobki, and he looks like a decrepit version of Sobek. He is a sweetheart, and the only citizen nicer than Sally.

-Carver later weaponizing drama to fight Pitch by using a lightning rod device to redirect a storm at Pitch. Took Finklestein's tools and left a silly pumpkin in their place.

Guardians elements:

• Pitch Black
  
  • Original bogeyman. Was the original ruler of Halloween Town, and was booted for getting too "power-hungry". He was known as the Shadow King. Jack has the title of Pumpkin King to differentiate. (+1)
  • Realized he had a life before this (+1) and rebelled against Primus for this. He had a daughter he was stolen from in life (+1), and sees LSB as the parallel to this, as they were stolen from their mother and made outcasts with no proper guardian (+1).
  • Primus changed him into Oogie to contain him. (+1)
  • Originally spirited LSB away as a "fuck you" to Primus, who was bringing them into the new Halloween cycle (-1), but in time actually grew fond of them (+1). His primary goal is to take down Primus, but he's convinced himself that he saved them from Primus (+1).
  • Legitimately fears they will be replaced. (+1)
  • Daddy Pitch! He legitimately wants them all to become a family. (+1)
  • Until his rebellious children rebel, and then he starts going off the deep end. (-1)
  • Started off using the trio as henchmen, and legitimately grew fond on them. (+1)
  • Forced personality change as Oogie as further punishment. This explains the contradictions between Oogie and Pitch's personalities, and the trio's legitimate fear of the former. (+1) Pitch is aware of this, but unable to do anything about it until Jack gets rid of the Oogie form. (+1)

Total sympathy points: 10

• Santa Claus
  
  • Starts off as NMBC!Santa. His frustration at Jack during the vents of NMBC ("To fix Christmas? Of course there is! I'm Santa Claus!") sets Primus off to prevent another Pitch and create a new holiday cycle. Santa was just stressed, but Primus took it as ego.
    
    • We actually decided Jack taking over Christmas is the catalyst, because now the holidays are aware other holidays exist, and that's a threat to Primus's power.
  • North is the new reincarnation.

• Primus
  
  • Originally meant for his holiday leaders to remain eternally. Pitch realized he has a life before this, and rebelled, which caused him to start cycling out leaders and citizens to prevent it.
  • Some of the original citizens in Halloween Town fade away and are replaced because they blindly followed Jack. LSB get to stay because they did their own thing.
  • LSB are aging because Primus wants to keep them in the new cycle, but not as children. Pitch will see this as him looking to replace them, because teens are already pushing it in terms of trick-or-treaters.
  • Agatha and the vampire twins were humans who Primus decided would fit. Not every citzen was once human, though. They don't question where they came from. Neither does anyone else, except LSB after a time (likely because Pitch planted that thought in their heads to awaken their memories).
    
    • Little Demons reference. LSB were Jonathan, Cynthia, and Bradley in life. This is what Pitch uses to a) start awakening their memories, and b) convince them that he is their father figure.

Approximate timeline of Halloween Town

1900: Jack dies and is raised as the new Pumpkin King; Shadow King is forcibly reincarnated as Oogie.
1920: Trickster Trio are spirited away by Primus and "adopted" as Boogie's Boys (ages 6,7,5)
1993: Jack's Christmas disaster. Oogie's body is destroyed, leaving nothing to suppress the Shadow King's sense of self.
2000: Primus decides to start new cycle and begins slowly switching out denizens of the holiday towns. Trio starts growing up. Carver is made. Shadow King begins rebuilding his power while Primus is distracted.
2010: Trio @ ages 8,9,7. "Sandy Claws" is reincarnated as North.
2020: Trio @ ages 11, 12, 10. Undersea Gal leaves.
2030: Carmilla and Lillith arrive. Trio @ ages 14, 15, 13.
2040: Agatha arrives. Trio @ ages 16, 17, 15.
2043: Trio approaching 17, 18, 16. Plot begins. Cyclops will disappear.

Current plot set-up:

-Prank set-up started in the second half of September. Since then, almost a month has passed: Lock and Lillith ditched practice, and then Shock and Carmilla fought the next week. They skipped a week to let things cool, and then did a test week to see where things are.

-Carmilla gets her actual revenge on Lillith for her and Lock's anniversary (Oct 13)
-Epic prank/raised tensions
-Halloween
-Barrel/Agatha awkward date
-Break-up
-Rival bands
-Vengeful dating?
-Pitch

Halloween Prank:

-Dr. F and the clock. It may not actually have happened yet.
-Carmilla confirms the date.
-Sally figures out the fog/well
-Jack can't recall anything from the day before, and realizes neither can anyone else. Mayor freaking the fuck out as his first clue.
-Witches figure out the forget-me-lots
-Lillith figures out it was on purpose. Lock told her a while ago Shock was up to something, and "You'll forgive me later."
-Agatha recalls she sold Barrel fog juice and sundew sap.
-The vampires can remember they saw Shock climb down from Town Hall not long before the fog hit. A few other citizens can verify she was in the square.

Putting any random OCs we come up with for later use here.

Halloween Town

• Sobki - Mummy Boy's older brother, based on the Egyptian god, Sobek. Town heartthrob. Has a crocodile skull for a head. He's a peacemaker, very kind, and a good cook. Doesn't like to hurt anyone (which later means Lock finds him frustrating in bed). Lillith's ex, though they broke amicably, and are still good friends.
• Chad/Wolfboy - a reverse werewolf who comes at a new moon. Wolfy is your generic nice citizen, a little skittish, but well-meaning. Chad is every handsome frat boy stereotype rolled into one. Tall, blonde jock who occasionally terrorizes Halloween Town. Accidentally crashed a party the tricksters were hosting years back because Wolfy was invited, but at the time, no one knew who Chad was. He learned the hard way not to mess with Shock, or hit on female monsters, as they now have a system to list jerks they avoid.
• Medusa - monster who lives in the sewer and is basically Halloween Town's wine mom for every teenager in town. After Jack, she's the one they respect the most.

Valentine's Day

• Cupid - as the name implies. Basically a well-meaning fanboy who hooks up his citizens as he sees fit. His ships vary from week to week.
• Adora - a romance-positive aro-ace under a curse and desperate to break it, but the "true love's kiss" caveat makes it difficult, as she can't feel romantic love, and has no context for other forms of love. She tries to date Shock, to disastrous results.
• Alex - a token Goth of indeterminate gender. Shock strikes out with them while trying to figure out this romance thing.
• Bernard - a big, loveable goof who forgets he's bigger than everyone else.
• Prince Henry - a Disney prince stereotype who gets to learn about heartbreak and that True Love's Kiss doesn't fix everything.
• Romeo and Juliet - gag characters in the background who try to get together, but Cupid keeps hooking them up with other people.
• Fabian - a Gaston type and Valentine's Town's version of Oogie in being that one resident who twists the ideology of the holiday for sinister purposes.

Spin the Bottle Shenanigans

Based on actual scientific dice rolls.

*1 - Chad - Always lands on himself first, no matter what speed/direction he tries. It lands between Carmilla/Agatha, and he accidentally sets the standard for no kiss if it lands between. Everyone else goes along with it.
2 - Sobki - Chad/Barrel (no kiss)
3 - Carver - Chad/Sobki (no kiss). These two get TL;DR’d
*4 - Carmilla - Lock (he declines)
5 - Agatha - Lock. She assumes Barrel’s helping rig the game and it wouldn’t be subtle if she landed on Barrel first. Lock gives her a quick peck on the cheek, then sits down.
*6 - Lock - Agatha. He laughs and comments how they *just* did that, and respins. Shock’s brothers are not immune to her toying with the game. Respin lands on Barrel. Barrel shrugs and gives his older brother a peck on the forehead. Lock exaggerates his disgust.
7 - Lillith - Barrel. She gives him a quick kiss on the lips. Barrel is confused because he just now realized this is part of the game’s trick, and it can backfire on him too.
8 - Barrel - Carver/Carmilla. Carver offers (“We both know Carmilla won’t, so I’ll do it. Also, I taste like popcorn.”). Barrel kisses, then jokes about how their pumpkin taste could be improved.

*1 - Chad - Barrel. Shock picked him deliberately because she thinks there’s a chance he might suck it up if it landed on Lock. He’s all, “no homo,” and Barrel, having figured out the trick now, pretends to pout. Everyone else is amused as fuck at Barrel’s lateness to the party re: game rules.
*2 - Sobki - Carver. They plotted with Shock to do this solely to piss off Lock and steal his thunder on the off chance he got Sobki. They dip Sobki for the kiss. Sobki is confused, but willing.
3 - Carver - Carver/Carmilla. Decides “fuck it” and offers a kiss to Carmilla.
*4 - Carmilla - Barrel (decline)
5 - Agatha - Lock - respin - Lillith (Agatha declines)
**6 - Lock - Sobki. Lillith messed with it this time because she really wants to see them kiss. Lock tops Carver by tossing Sobki up in the air, catching him, then dipping him. Sobki is once more confused, but willing. Lock flips Carver off while kissing. He decides to get a victory drink, and that's when he starts declining into tipsiness.
7 - Lillith - Lillith/Barrel (no kiss)
8 - Barrel - Agatha. Gentlemanly kiss due to height differences. Agatha swoons. Barrel is none the wiser.

*1 - Chad - Sobki (decline due to Sobki’s teeth, and also no homo)
2 - Sobki - Carmilla (declines like a goddamn gentleman)
3 - Carver - Lock/Agatha. “Cool, I get to kiss both of you!” Chad’s jaw drops. “That was an option?!”
*4 - Carmilla - Agatha (friendly cheek peck)
*5 - Agatha - Shock lets the bottle slow down as it approaches Barrel to get her hopes up, then continue on to Chad for horror factor, then it stops between Chad/Sobki. Agatha is relieved that it skipped over Chad and a smidge disappointed it didn’t quite get to Sobki, since Barrel showed earlier he doesn’t mind kisses in the context of the game and doesn’t consider it cheating.
6 - Lock - Lillith. He is very tipsy by this point, complimentary, and pretty much all over Lillith anyway. She kisses him to make him STFU. Agatha thinks this is where Barrel learned how to be a gentleman, because he damn well didn’t learn from Shock.
7 - Lillith - Agatha/Carmilla. Shock senses trouble potential and changes her mind about playing. She doesn’t know who is getting pissed or why, but she puts effort in it to get a trouble fix - and because she expects Chad to act inappropriately, which he does. She ends the kiss to boot him, but Barrel beats her to it.
8 - Barrel - Doesn’t get a turn because Shock derailed the game. Agatha is simultaneously relieved that Chad’s getting booted and pissed because she was certain that she was going to get the “real” kiss this time. Game changes to roulette.

* = Shock fucking with the game
** = the one time Lillith fucks with the game