Halloween World

In the world of Buffy the Vampire Slayer Crossover fanfic, no plot is used quite as much as the YAHF (Yet Another Halloween Fic) story. Halloween World takes this somewhat overused idea to its absolute extreme with a few unexpected twists.

On October 31, 1997, the spell cast in Sunnydale by Ethan Rayne went drastically out of control. Instead of turning a few people into their costumes for the night, the spell engulfed the entire world, changing people into their costumes permantly and filling the whole world with monsters. The chaos magic also had a number of effects on the environment, most notably turning the sky red and casting the world into a state of perpetual night.

Thus is the setting for an over the top and decidedly epic Mega Crossover that includes characters from almost every piece of fiction under the sun. Unsurprisingly, the series is utterly Troperiffic, since the various crossover characters brought their rules and tropes with them.

Much like the spell that started everything, the series seems to have gained a life of its own. The main story was written by spaceman, but there are numerous spin-offs by other authors.

Tropes used in Halloween World include:

After the End
Alternate Character Interpretation: there are a number of characters who are living examples of this trope in action. As the author put it, perception is the basis of reality, so different versions of the same character differ according to the character interpretation of the person who wore the costume on halloween.
Alternate Universe: The story itself, obviously. There are also several characters who are alternate universe versions of each other.
Apocalypse Not: Justified since given the amount of firepower, magic and Sci Fi level technology that's around after the Event humanity and equivalents were more then able to survive, adapt and develop.
Author Avatar: One does appear once, but he has very little relevance to the plot. There's also an avatar of a frequent reviewer who makes a few appearances.
Badass: About 90% of the population. Non-badasses tend not to live very long.
Badass Creed: A few examples:
- "Ashes to ashes, dust to dust. I will survive and Hollow killing is a must."
- "We don't fear death. We don't fear life. We adapt and we survive. We are the warriors of Hallow Earth!"
- "Killing is acceptable, murder is a sin" and variations thereof.
Badass Family: There are numerous examples, one of the most (in)famous and terrifying being what you get when you combine three versions of a certain bell wearing Blood Knight of a shinigami, a number of women who are as crazy as he is and an out of control lust/fertility spell to kick start things. Four words: second generation Blood Knights.
Blessed with Suck: There are a few notable examples. For instance, there's a guy who went as Naraku and got through Halloween with his personality intact. Unfortunately, his mum went as Kikyo and wasn't as lucky. Gaining the abilities of a powerful bad guy while keeping your own personality may sound like a good deal, but when your own mum tries to kill you due to mistaking you for said bad guy it's a different matter altogether.
Boring Invincible Hero: The good guys never lose and only a couple of them have died. On the other hand, the war does go on for almost twenty years and the 'offscreen' death toll is pretty high, not to mention that while the important characters survive the unnamed ones get slaughtered.
Chuck Cunningham Syndrome: The absence of Spike, Drusilla, or, most jarringly, Angel is never pointed out by any of the characters. Subverted in that they do get their own side story instead of just disappearing.
Cursed with Awesome: Even curses that were detrimental in a given characters universe can become extremely useful in Halloween World.
Dark Is Not Evil: For one reason or another most of the world's population are dark to some degree so this particular trope is a fact of life.
Demoted to Extra: All of the BtVS cast except Xander post-timeskip. They do occasionally get their moments in the spotlight, but it tends to be fairly short lived.
Depopulation Bomb: It's stated outright that billions of people died after the Halloween Event.
Death Is Cheap: Lampshaded to hell and back. One of the side stories even has the trope name as a title.
Enemy Mine: Finding yourself in a world of monsters has a way of changing your priorities and a lot of former enemies find themselves working together in order to survive and/or fight the Big Bads.
The Eternal Churchill: Humanity, plus equivalents and allies, ends up fighting a world war against a mixed bag of Big Bads for almost two decades.
Extranormal Institute: Several are mentioned throughout the series.
Face Fault: Thanks to the large number of anime characters, the physics of the 'verse have been altered to make face faults extremely common.
Fire-Forged Friends: See Enemy Mine.
The Four Gods: Naraku's Quirky Miniboss Squad
Four Is Death: Several examples, but the four final BigBads are probably the best example.
Genius Loci: Citadel City.
Half-Human Hybrid: Very common. Examples in the main story include human/demon, human/youkai, human/alien and human/shinigami. One of the side-stories has human/passling and human/bear (both cases involved a very over powered and out of control lust/fertility spell) while another has a reference to human/Arrancar. That's without even going into all of the half anything but human hybrids.
Heinz Hybrid: Take a world populated by pretty much every fictional species ever thought of, add one or two out of control love spells plus a few other motivating factors and, as one reviewer put it, it's safe to say that what passes for humanity in the Hallow-verse is well on its way to an advanced state of muttiness.
Heel Face Turn: Numerous examples, one of the most blatant being the fact that the forces fighting on the good side in the final battle against Aizen included former Espada. As one of them put it, "Following him didn't turn out well in our last life."
Horsemen of the Apocalypse: Griffith's Quirky Miniboss Squad.
Improbable Species Compatibility: Happens with a number of species, but Pokémon/Yokai hybrids are mentioned several times.
Inferred Holocaust: After a fashion. There are plenty of survivors and they seem to be doing well, but between a quick and dirty form of natural selection (it's nigh impossible for a normal human to survive without protection from a colony or someone with superpowers) and the knock-on effects of the chaos magic, humanity as we know it is pretty much scuppered.
Info Dump: A lot, usually from the narrator.
Interspecies Romance: See Heinz Hybrid example.
Loads and Loads of Characters: The pre-timeskip arc introduced a handful of characters every chapter, until the cast was well over a hundred by the end of it. The post-timeskip arc introduces so many characters per chapter that it can be a little difficult to keep up.
Mega Crossover: Mostly anime.
Magitek: There's a heck of a lot of it, used for pretty much everything.
The Night That Never Ends
One-Winged Angel: Used several times and lampshaded at least once.
Original Character: Most of the character come from some canon, but there are several notable original characters. Due to the nature of the Halloween Event there are also numerous examples of the latter in the bodies of the former.
Psychopomp: Every conceivable version thereof. On of the side stories even featured them having a meeting to sort out how they were going to work together. Interestingly, the living can see them, know what they are, and following the timeskip at least don't seem to be particuarly bothered that Death is literally walking the streets.
Quirky Miniboss Squad: Each of the final Big Bads have one.
Red Sky, Take Warning: The Red Sky, a part-electromagnetic, part-magical barrier that doesn't allow anything to go through it, fries almost all forms of aircraft and periodically unleashes various kinds of hell on the world below.
Ruins of the Modern Age: The story includes frequent mentions of ruined cities, most notably Los Angeles.
Serial Escalation: It's safe to say that the latest plot arc qualifies.
Spotlight-Stealing Squad: Xander gets far more attention than any other BtVS character.
Slept Through the Apocalypse: One of the spinoff stories involves a man who went into magically induced suspended animation in a desperate attempt to survive terminal cancer. He spent seventeen years in a locked trunk before being discovered by chance and revived. Fish Out of Temporal Water, Values Dissonance and Post-Historical Trauma ensues.
Time Skip: The first arc is set in the months after the Event; the second kicks off 12 years later.
Translator Microbes: Done in a rather original way, namely a 'viral language' that spreads faster than the common cold.
Translation Convention: It is heavily implied that post-timeskip people's original languages has been largely replaced by the above mentioned viral language. To the reader of course, everyone's speaking English.
Troperiffic
Unwanted Harem: Xander's wives, though the unwanted part is dropped post-timeskip.