The Conversion Bureau

""Human bodies are icky and big and ugly and...and mean! Humans are mean!""

- Pinkie Pie

"“Humans are harsh creatures, but they have to be because their world is harsh and dangerous. Sometimes in their pursuit to survive, they cross each other, and most times they make friends and can work together, but other times it doesn’t work out and they feel that they have to fight. They are mostly good, I think, but sometimes they just plain old turn bad .... and live to cause other humans misery.”"

- Twilight Sparkle (Yellowstone Continuity)

A My Little Pony Friendship Is Magic fanfic, which has in turn spawned other stories by other people, using the same setting.

It is set in on Earth, in the future, where the island of Equestria has suddenly appeared. Earth is not in the greatest shape due to humanity, and the location of Equestria is pushing into Earth territory, with the magic emanating from Equestria being lethal to mankind, and in order to set things right, Princess Celestia needs to send out a powerful wave of magic that will restore the planet, but kill all of humanity. In order to help, Celestia sets up conversion bureaus all around Earth, letting the humans become ponies... though the problem here lies that the converted humans' personalities change.

It can be found here. and many of the spinoff fics can be found here.

The fanfic shows the following tropes:

 * Can’t Argue with Ponies
 * Emergency Transformation: The basic premise on the most part. It's either move away, succumb to the magic/radiation of Equestria and perish, or become a pony.
 * In addition, one of the draws of the ponification serum for many is that the process instantly and fully heals the imbiber, even going so far as to remove diseases or genetic defects. Several stories feature humans on the verge of death taking the potion to save their lives.
 * Fantastic Nuke: the purification spell.
 * Fantastic Racism: Goes both ways. When humans hold racist attitudes toward ponies, it's considered evil, but when ponies hold racist attitudes to the point of killing the entire species, it's considered proper and justified.
 * Gone Horribly Wrong: Blaze states that he only wanted to explain why Equestria had no humans. Instead, he attracted a sizable Hatedom, some crazy authors and a permanent reputation as a misanthrope.
 * This is probably the reason why most now Hand Wave the "no humans" by having Equestria as being on another planet with the humans serving the role as aliens or The Fair Folk.
 * Humans Are Bastards: One of the more infamous things about this story.
 * Les Collaborateurs: It's mentioned that human scientists helped develop the ponification serum. Additionally, the world's leaders seem to have no interest in stopping what the ponies are doing.
 * Misanthrope Supreme: The ponies in general.
 * MST: Most notably one by the same people who are covering the first draft of Past Sins, but the sheer moral and ethical issues this concept raises and then flippantly discards has painted a giant bullseye on the series.
 * Not Himself: Getting transformed into a pony fundamentally alters one's personality. This is treated as a good thing.
 * The Right of a Superior Species: The ponies think that they have the right to exterminate humanity because they feel that they are more "civilized" than humans.
 * The Sadistic Choice: Humanity as a whole faces one: Lose your body, mind, and culture, or die pointlessly?
 * Scary Dogmatic Ponies
 * The Social Darwinist: The ponies, type 3.
 * Superior Species: The ponies, to an absurd degree.
 * Wish Fulfillment: Pretty much the reason why it's so popular.
 * Would Be Rude to Say Genocide: Type A.

General

 * Affably Evil: Many members of the Ponification for Earth's Rebirth (PER) movement meet this description. They are almost unfailingly friendly and polite, and will usually begin a conversation with a human by trying to reason with them and convince them that getting converted is the best choice. If the human disagrees, however...
 * Baleful Polymorph: Some stories have forced ponification as a response to the Human Liberation Front and humans that like being humans. Ponies usually see it as better alternative to killing them, but those getting changed disagree.
 * Deconstruction: A lot of them. The most well known is The Conversion Bureau: Not Alone
 * Don't You Dare Pity Me!: Discussed in Railroad Seven-Three. The average native Equestrian claims to pity humans rather than hating them; many humans in turn resent this. Balthazar in particular despises Celestia for what he views as an incredibly condescending attitude.
 * Driven to Suicide: In one of the fics, Twilight mentions that a few of the remaining humans chose this instead of facing the restoration magic or getting ponified.
 * Generic Doomsday Villain: The Human Liberation Front hates ponies and anyone who sympathizes with ponies. And... that's about it. They never receive sympathetic PO Vs, and any story where they act as more than faceless mooks is rare.
 * Gender Bender: The beta version of the ponification serum could only create female ponies. There are a few stories where it is accidently given to a male.
 * Humans Are Flawed: Some of the spin-offs take this attitude in contrast to the original. Many have protagonists that are and remain human, become good friends with ponies, but does not sweep away the fundamental problems with humanity being apex predators descended from pack-hunter gatherers.
 * I Did What I Had to Do: In Last Man Standing, Celestia confirms the suspicions of many in a conversation with the last remaining human: she DID invade Earth deliberately. However, she points out that due to the merging of the worlds, either Equestria or Earth was going to be destroyed no matter what; she simply chose to try and save her subjects.
 * The Mind Is a Plaything of The Body: Turning into a pony fundamentally alters your personality. You keep all of your memories, but become much more predisposed towards happiness, nonviolence, and social interaction.
 * NGO Superpower: Some fics depict the Human Liberation Front as having Super Soldiers in Powered Armor or even doomsday weapons.
 * Physical God: Although Celestia was already a goddess in canon material, TCB stories tend to ramp this trait up to the extreme. Celestia is almost always completely unstoppable, and sometimes even omnipotent.
 * Screw You Ponies: The "Ten Rounds" universe features this in spades, with the human characters resisting the Ponification to truly epic lengths. One called Ten minutes ends with.
 * Self-Insert Fic: The main premise of most.
 * Transhuman Treachery: Once a person goes pony, they may still feel attachment to individual humans. Any sense of love for the race as a whole is long gone, however, even if they ardently supported it before.
 * What the Hell, Hero?: One of the main themes behind The Ballad of the White Rose. A group of rebellious young ponies discover that the death of humanity was no accident, and decide that Celestia has a lot to answer for.

Jennifer Diane Reitz (Chatoyance)

 * After the End: The Earth's ecosystems have all but completely collapsed, the population has been ravaged by disease, vast stretches of urban and suburban development have been abandoned, and the human population is dwindling rapidly as humans are ponified.
 * A Form You Are Comfortable With: Celestia, Luna, and Discord all have bodies composed of pure magic. It's still enough to make most corporeal onlookers uneasy.
 * Airstrip One: Earth's One World Government has grouped the former nations of the world into administrative zones. Most people still refer to specific regions by their old names.
 * Alien Geometries: Equestria's reality is a flat plane, rather than a planet. There is no “edge” to the land; traveling in any direction will eventually loop back around on the other “side”. Theoretically, this should apply to upward and downward travel as well, though no one has ever tested it for reasons that should be reasonably obvious.
 * Armies Are Evil: Blackmesh Security openly advertises their dedication to enforcing the will of the oppressive Corporate Worldgovernment, and uses the opportunity to brutalize malcontents as a recruitment enticement.
 * Artificial Intelligence: In New Universe One: The Pony Singularity and New Universe Four: Phoenix In Hooves.
 * Author Appeal: GLBT themes, transhumanism, androgyny, alternate dimensions with alien physics and strange geometries.
 * Author Tract: New Universe Three: The Friendship Virus has nothing to do with The Conversion Bureau stories other than some name-dropping that could easily be exchanged with anything else. It's a retrospective tale of a world wherein a group of bioterrorists calling themselves “The Conversion Bureau” were inspired by My Little Pony: Friendship is Magic to bring about a pacifistic utopian world by creating and releasing a DNA-altering virus that eliminated most differences between genders. Genetic tendencies towards aggression and territoriality were rewritten, oxytocin production increased, but most importantly – as emphasized by the narrator's thoughts – testosterone production in males was cut down to one third. The result is that men have become identical to women in every way save for their primary sexual characteristics. In this new idyllic world, all traces of masculine behavior have been abandoned. Crass displays of machismo such as rough sports and violent movies have been abandoned, recognized for the barbarism they represented. War, rape, and civil strife are things of the past, now that the vile mind-control toxin testosterone no longer drives men to commit 98% of the world's violence.
 * Apocalypse How: Class X: Planetary Annihilation
 * The Bad Guy Wins: In New Universe Seven: Mankind Triumphant!,
 * Big Brother Is Watching: Earth's government. Also, Celestia, within her own dimension.
 * Bittersweet Ending: On the one hand, the Earth is destroyed, the human species is extinct, all the humans who've ever died were lost forever, and those who have become ponies are defenseless slaves to an insane goddess, their minds altered such that they are no longer capable of wholly grasping the horror of their situation. On the other hand, the Earth was wrecked beyond repair, mankind was in decline, and the ponified humans are now part of the ponies' cycle of reincarnation, shepherded by a being who is pleased by their happiness.
 * Body Horror: Skimping on the ponification serum causes the person to die horribly as they are locked between human and pony form.
 * The human form is this to some members of the PER.
 * Category Traitor: “Species traitor” is used on at least one occasion.
 * Cerebus Syndrome: Other than the usual unfortunate implications and expected plot elements common to most TCB works, JDR's stories were pretty innocuous until The Taste of Grass began developing Celestia's character and fleshing out the setting's details.
 * Cessation of Existence: The fate of humans – and only humans. Every other sentient species in every other possible universe gets an afterlife of some sort.
 * Corrupt Church: Earth's religions. All of them. In fact, the concept of religion is regarded as evil.
 * Cosmic Horror Story:
 * Crapsack World: Earth's ecosystem is completely destroyed, the entire planet is governed by a corporate conglomerate, social mobility is nonexistent, and the employment rate is frozen at 2%.
 * New Universe Two: The Most Decadent Thing exchanges the corporate hellhole for a hedonistic transhumanist equivalent of Idiocracy.
 * Cyberpunk: Several elements of the genre are present in her stories.
 * Democracy Is Bad:
 * Despotism Justifies the Means: Celestia's #1 priority is being the final authority in Equestria.
 * Did You Just Punch Out Cthulhu?: In New Universe Seven: Mankind Triumphant!, humanity disposes of Discord by running his petrified form through a rock crusher. They then
 * Dystopia: Earth. Possibly Equestria, not that the ponies are capable of realizing it.
 * Eldritch Abomination: Celestia and Luna.
 * Fantastic Racism: Each of the three types of ponies thinks themselves better than the other two. It most certainly is not in any way comparable to human racism.
 * Fix Fic: Ten Minutes: Aftermath was written as a response to the pro-human sentiments of the original story, intentionally subverting the message of the original in order to fit the author's own work into JDR's setting.
 * Foreshadowing: In Teacup: Down on the Farm, the titular character experiences a brief and horrifying panic attack that later stories reveal to be a surprisingly accurate insight into Equestria's reality.
 * Grey Goo: In New Universe Four: Phoenix In Hooves, Earth has been entirely devoured by grey goo.
 * Heaven: The afterlife for ponies, where they dwell until they are reincarnated.
 * Hobbes Was Right: With regards to humans, and only with regards to humans. Other species just naturally get along.
 * Humans Are Bastards: JDR loves this. Even going as far as to argue this point in the comments, sometimes in other stories.
 * Humans Are Flawed: See above.
 * Humans Are Morons: Again, see above.
 * Humans Are Special: Humans are the only known lifeforms to have evolved in a universe completely devoid of magic. As a result, they're also the only sentient beings to lack actual souls.
 * Hypocritical Humor: In Going Pony two characters explains the “science” behind the process of ponification, stopping to wonder aloud why humans always try to explain away magic.
 * Ignored Epiphany: In The 800 Year Promise. The protaganists consider the villain's dying words and admit that he was probably right... then disregard the topic and never mention it again.
 * Immigrant Patriotism: Many newfoals are incredibly enthusiastic about doing things the proper Equestrian way.
 * Mad God: Celestia
 * Magic Versus Science: Science and technology derived from it are inherently destructive to the environment. Magic can do anything science can achieve and more, all without harming anything.
 * Manipulative Bastard: Celestia is good at ensuring that events work in her favor. The only time she's failed to manipulate a situation to reach her own goal involved temporal and spacial shenanigans spanning two alternate realities, one of which she has minimal power within.
 * Mechanical Lifeforms: In New Universe One: The Pony Singularity.
 * Medieval Stasis: The show's cities and magitech are explained as being the leftover products of the Ponies' flirtation with industry, which was abandoned when the ponies realized that Technology Is Evil.
 * Mega Corp: The Corporate Worldgovernment, which owns the entire world, and Blackmesh Security, which serves as their military police.
 * Misanthrope Supreme: The ponies. Even more than in the original. Terrifyingly, JDR approaches this.
 * One World Order: Earth is ruled by the Corporate Worldgovernment. Equestria is ruled by Celestia.
 * Peace and Love Incorporated: Played straight by the Conversion Bureaus, in that they're not actually about saving humanity. Averted in that they really do care.
 * Perfect Pacifist People: The ponies are completely incapable of any degree of violent action, even in self defense.
 * Privately-Owned Society: Earth.
 * Purple Prose: Seemingly the author's primary means of communication.
 * Reincarnation: Ponies, eventually.
 * Ridiculously Cute Critter: Ponies.
 * Stable Time Loop: Derpy.
 * The Multiverse:
 * The Soulless: Humans
 * Third-Act Stupidity: In The 800 Year Promise. Ralph and his HLF coconspirators are clever enough to hide amongst the ponies of Equestria for years. They've got agents at every level of Equestrian society – even in the palace, so there's no running to Celestia for help. All throughout the story they're one step ahead, always having figured out enough to know where they should be looking before the protagonists do. They've fabricated a cover story for anyone who questions them. They know enough about dragon culture and history to attempt to rouse them to anger against Celestia. Four chapters from the end they walk into a dragon's cave, beat up his “guests”, and die horribly when he comes home.
 * Unperson: Beings who become a “problem” for Celestia have a tendency to disappear. Later, some lucky civic area is gifted a surprisingly lifelike new statue. It's unclear how or if their disappearance is explained to friends or family, but it's clear that, aside from Discord, nobody hears about them in any history lessons.
 * Unwilling Roboticisation: The plot of New Universe One: The Pony Singularity.
 * Utopia Justifies the Means: Celestia's #2 priority is keeping Equestria a paradise for her ponies.
 * Villain Has a Point: Before dying, Ralph explains what the final members of the HLF have come to believe about Celestia, the destruction of the Earth, and the true nature of Equestria. Sharptooth, the only character present that is familiar with the princess, not mentally rewired to obey her, and knowledgeable enough about the universe to make any assessment of it all thinks he's right.
 * Well-Intentioned Extremist: The PER.
 * Writer On Board: And how!
 * You Cannot Grasp the True Form: Celestia sometimes gives mortals a glimpse of her true form when she wishes to terrify them into submission.