I Am Not Left-Handed: During her fight with Rarigreed, Dark World!Fluttercruel reveals that she can use her mother's ultimate weapon: The Stare. She comments that Discord specifically told her to not use it around the other Elements of Chaos, so that she could surprise them with it if they ever turned on Discord.
It turns out that Shining had been holding back the true extent of his shield magic because the last time he used it, his uncle had just been killed and he crushed the Diamond Dog that did it to death.
I Am Not My Father: Fluttercruel and Fluttershy consider Discord Fluttercruel's father, but she has no desire to follow in his footsteps, but doesn't go out of her way to go against it. Fluttershy is adment that having an evil father doesn't make her evil. Then Fluttercruel actually DOES follow in his footsteps and corrupts Fluttershy worse than Discord did. After fighting her way back to the world of the living, she is more than ready to do exact opposite of what Discord would do, leading to this little exchange:
Undead Foal: Move you stupid half-Draconequus!
Fluttercruel: That's stupid little pony!
Also with Fluttershy, who, due to being her basis, considers herself Fluttercruel's mother and treats her as such. Fluttercruel pretty much wants to be anything but Fluttershy.
I Am Spartacus: When Traitor Dash shows up in Cloudsdale and demands that the hippogriffs hand over the resident Rebel Leader, the entire crowd does a pretty good imitation of the Trope Namer scene. Dash Sherlock Scans the actual target and kills her. The sad part is, she had no choice. She had to kill someone or Discord would destroy the city.
It does have an impact, however, as it's one of the things Twilight's Memory Spell reminds Traitor Dash of to break her Discording by showing the Dark World is still worth saving.
Idiot Ball: Half of why Chrysalis is getting her way, combined with a dash of Easy Logistics - Somehow almost ten thousand Guardsponies can be replaced by "Rookies" in the Canterlot area with a known threat? None of the many other higher ranking officers ever objected to this? No one spots the different communications between units?
Dark World!Rarity takes back her original name, but keeps her Rarigreed and Greedity names and gains a new name, Lady Desire, from the Diamond Dogs. Being the Element of Desire, it fits her. She also gains Queen Libra upon becoming an Alicorn.
Dark World!Discord has seemingly infinite titles, the majority of which are nonsense such as 'Big Banana Discord'. It's unknown if the same applies to the main timeline Discord or not.
I Just Want to Be Special: Trixie, due to her Middle Filly Syndromeand being unable to stand out among her four near identical sisters. It got worse when she went to magic school and was unable to excel at anything in particular. This caused her to overlook the fact, as her teachers told her, that she could do almostanytype of magic well, including weather magic, which is very rare for a unicorn to be able to do at all. She gets her wish, however, when it's revealed she's an Element Of Magic and has just as much unrealized potential as Twilight Sparkle did, but Trixie still has some issues with being Twilight's "alternate."
The Mane Six try this fighting Nightmare Whisper, Fluttershy's Superpowered Evil Side, but it's only after blasting her with the Elements of Harmony and purifying her that they're actually able to reach her.
Most of the fights in the Dark World with the still corrupted Mane Six. All three succeed, but with increasing amounts of difficulty each time, Rarigreed being the easiest and Angry Pie the hardest.
Derpy keeps trying this with the Valeyard. Subverted in that the Valeyard really isn't the Doctor and therefore there's nothing to reach. The only way to restore the Doctor is to destroy the Valeyard's regeneration template, then kill him, allowing him to regenerate back into the Doctor, which DOES work.
Imaginary Friend: Pinkamenia had several, the same ones from "Party Of One", only in her imagination, they were real ponies. They were killed and absorbed by Angry Pie, though. Trixie had Princess Starflower, but left her behind after becoming a star, but Twilight found her while in Trixie's head and she helped her save Trixie. Both come back when the gang areunder Princess Gaia's spell and break Pinkie Pie and Trixie out of it.
Clover's Gaiden story reveals that Pinkie herself was originally Clover's imaginary friend, brought to life by the world changing spell. This causes Pinkie to have a Heroic B.S.O.D. and nearly lets herself be dragged to Oblivion by the Shadows of her friends before Twilight, Zecora, and Luna convince her she's as real as them.
Princess Luna had her own imaginary friend that is an owlbear named Olo.
Olo the Owlbear and Princess Starflower become alive in the Finale arc to help out their respective owners (Olo is specifically with Moooonlight, Luna's avatar). They are created from the benevolent rumor parasites.
Turns out the Elements of Chaos themselves were originally the Elements of Harmony. If you need proof, besides Word of God we also have the fact that when Angry Pie tore out Twilight's Element of Magic and left her to die of Rapid Aging, Twilight saved herself by taking in Trixie's Element of Magic, since Trixie was one of the ponies who had died in the thousand years of the Dark World and didn't need an Element that she had never managed to awaken in this timeline.
Implacable Man: The Chaos Six were seen as this by the denizens of Dark World, being they're immortal Co-Dragons of Discord. As shown later taking on Discord's Mooks, against normal enemies, they're still this, it just happens they were fighting otherImplaceable Men until then.
The Wolf/Stalker from the Shining Armor Arc. A mysterious entity that's dedicated to erasing Shining Armor from existence,nothing will stop it from completing its objective. Not gun fire, not shield spells, not walls, not even being caught point blank at the center of an explosion, followed by the tripod it was attacking toppling into the ocean and exploding. It's been stalking Shining across countries and so far, the only things that can slow it down are Makarov's Death Dome spell (something Shining has tried to replicate and failed) and Princess Cadence's presence. There's very good reason Shining Armor is absolutely paranoid of the thing.
I Need a Freaking Drink: Trixie is told, on short notice, that she'll be doing a magic show at the celebration for Princess Gaia, with no practice, no props, and pretty much nothing to work with. Her reaction is to find a bottle of sake with salt and get very drunk.
In Mysterious Ways: Subverted with at least the Alicorn Elders, who will give a logical explanation for their actions whenever they're asked, such as Applejack asking why the Father didn't just tell her she was the Element of Kindness (she'd have just saw it as a lecture to ignore), and Dark World!Twilight asking Fauna Luster why the Alicorns didn't stop Eclipse (because Eclipse was too strong to safely fight, but not yet a big enough threat to justify the Elders confronting her directly).
Despite the unforeseen events of Windigos, the Alicorn/Draconequus War, and Discord's first reign, the Ponyville designed during Generation Transitions still comes into being exactly as planned, three characters excluded.
Several aspects of the world tour Shining and Cadence's group is on still happened after Makarov was erased from existence such as there still being a fight in Columbia (though it involved a Nightmare Moon cult) where Audience and Ellis got promoted and Cadence still got her song bird and had to power up (though this time it involved an Eldritch Abomination). Justified as it's implied Makarov devoured and stole the places of the ones who were originally involved, such as the leader of the Nightmare Moon cult.
Flash Sentry, in his memories of the future (from his current perspective, time travel is involved), thinks that if Nightmare Diamond hadn't been speeding up the degrading of Camp Everfree, Gaea Everfree would still have snapped and went Nightmare, but only after the humane seven left when Filthy showed up, which naturally would've made things much worse.
Instant Fan Club: After Princess Gaia's rule, Fluttershy results in getting a sizable following due to how much it healed many ponies. Her popularity as a fashion model not withstanding. [[Which, according to the Shining Armor arc, has reached as far as the kingdom of Neighpon (a spoof off of Japan), where she still has a strong fan-base. She even still receives fan letters from them, though she cannot read them due to being Neighponese.]]
Interservice Rivalry: Shining Armor states that this is good for morale... right after stating that the Day Guard are wimps and the Night Guard is afraid of the light (and ignoring the fact that he was a Day Guard before being put in charge of Cadence's branch of the Royal Guard).
However, one that Shining doesn't approve of is the one between the 18th Pegasus Legion and the Pegasus Guard, who loath each other over their opinions on the Wonderbolts. Upon discovering all three are going to be in Zebrawa, he is none too happy about it. Thankfully, Cadence manages to turn things a little more friendly though.
Ironic Echo: A keen reader would be able to spot when two different characters, without ever having previously heard it, say the same phrase in entirely unrelated contexts.
"If they really believed it they wouldn't be saying it every time they said something" — G3 Pinky & Onyx Tiara
Twilight: Time march forward. Bonds reach across all.
Twilight/Minty Pie: We'll wander no longer!
Ironic Hell: Dark World turns out to be this for Discord, inflicted on him by Nightmare Eclipse. His kingdom will never end, his mistakes are always undone...forever.Never to end. By the time she's defeated and he's freed, he considers being killed over and over again by his family for his crimes relaxing in comparison.
Dark World!Fluttercruel is punished for her crimes via one of these. She's inserted into the past as an Earth Pony named Stitches, who's family was slaughtered by Fluttercruel, and ends up being one of her own victims. The experience ends up triggering a complete Heel Realization and Villainous B.S.O.D. that finally reforms her.
Irony: The irony does not escape Fluttercruel that she was made by Discord with the first words she heard being "Time to be cruel" and she becomes not only an Element of Harmony, but an Element Of Kindness.
It Can Think: The Moochick and Heathspike are surprised to find the primitive ponies building the beginnings of their civilization as before then they'd only known ponies as nonsapient animals. Justified as the ponies only recently became sapient a number of years prior.
It's Personal: Shining Armor says this is the case with Makarov when he seemingly threatens Twilight's safety. Subverted in it was actually Dima, who needed to get a hold of Shining for help stopping Makarov and never intended to hurt her at all, so Shining forgives him. Double Subverted when the same chapter, Makarov makes it after trying to destroy a village of innocent zebra and ponies, killing dozens, tries to make Cadence his concubine, and is revealed to have kidnapped several innocent ponies and condemned them to an And I Must Scream fate by converting them into his Co-Dragons. This results in Shining Armor and his group declaring that This Is Unforgivable!, something that's Serious Business to Equestrians, who have forgiveness as a cultural value.
If Makarov didn't do it then, then he certainly did by blowing Running Gag's wing off, giving Misfit Actual a No-Holds-Barred Beatdown, and trying to murder Twilight while Shining is Forced to Watch.
It Sucks to Be the Chosen One: In the Finale Arc, the CMC ask why they are the ones who have to save the world, pointing out they are only children.
It Was a Gift: Diamond and Silver gave each other dresses one Hearth's Warming as part of an excuse not to get in trouble. They still kept them even though they hate the dresses themselves...
Jerk with a Heart of Gold: Fluttercruel starts out as just a Jerkass, but Fluttershy's careful work with her ultimately turns her into this. She's still a jerk, but she at least willing to help Fluttershy out.
We find out when we see things from her point of view that Fluttershy didn't make her come out to help calm Rainbow Dash, she forced herself to the surface in order to do it. And even when she takes over, the worst she does is pull Fluttershy's leg a few times, showing she's nowhere near as much of a Jerkass as she originally was.
By the end of the battle against Nightmare Whisper, Fluttercruel is not only fiercely protective of Fluttershy (to the point of being willing to sacrifice herself to save Fluttershy and her friends), but is also able to manifest an Element of Kindness. She still acts like a jerk a lot of the time, though.
Silver Spoon. She was only a bully because her only friend Diamond Tiara was, she's truthfully a much more loyal and kind friend than would be expected at first glance. This is also hinted to be the reason for the heart in the spoon on her Cutie Mark.
Jump Scare: Done incredibly well in the audio adaptation, during "REHARMONIZED PONIES 06: House Call".
Jury of the Damned: Fluttercruel ends up in one of these after what appeared to be her death, with a court of demonic shadows ruling on whether or not she should exist. The find her guilty, but she fights her way out of it to help the heroes defeat Princess Gaia/Nightmare Whisper and fix the mess she was responsible for. It's left ambiguous as to whether or not this was real or all in her head.
Starlight finds herself in one after dying in the G2 Era's Class 2 apocalypse, being on trial for her role in said apocalypse. In an unusual case, she's both the defendant and the judge, with Judicium, the Alicorn of Judgment, serving as her adviser. She finds herself guilty at the end. In another twist, her Defense Attorney was actually Havoc, the Dimension Lord of Hell, and that declaring herself innocent would've condemned her because it means she's refusing to accept responsibility for her actions. The Prosecutor was actually the Father of All Alicorns, the Dimension Lord of Heaven who was trying to get her to accept that responsibility and ask forgiveness so he could give it and let her into Heaven.
Karmic Death: The blackbirds that have tortured Dark World!Derpy for a thousand years by trying to eat Dinky (who has been turned into a muffin), are ultimately thrown into Ponythulhu's dimension to be eaten themselves, also by being turned into a baked good.
There's also Dark World!Discord meeting his end a similar way to how he killed Destruction; being betrayed by a sibling and having Destruction's power torn out of him.
Nightmare Eclipse/Paradox ends up suffering the same fate she forced on Twilight so many times; seeing her friends being torn away from her before being forced to merge with Twilight as part of her Alicornification. Rota Fortuna even lampshades this.
Rota Fortuna: …You are right. Crimes are crimes, and we should never turn a blind eye to them. You who have judged others, you too shall be judged.
Karma Houdini: Played with in the case of General-Admiral Makarov in Shining Armor's Arc. On one hand, he gets no direct retribution for his attack on Shining Armor. On the other, he's been reminded that he's not the biggest fish in the sea (and that the combined special forces of SEVERAL nations will be actively working to bring him down should he try again) and had his ego thoroughly bruised, which considering his ego has to hurt. He was also threatened with being declared a Persona Non Grata in multiple countries. Subverted ultimately, as he's erased from existence as his final punishment.
Karmic Jackpot: Happens to both the Mane Six and the CMC during the Rumors Arc after the CMC save the universe. Scootaloo finally finds out who her parents are and why they abandoned her, Applebloom is given the opportunity to alter reality to make it better for everyone (and takes it), and all three Crusaders gain the shields around their Cutie Marks as in canon. As for the Mane Six? One of the alterations Applebloom made was giving them a statue in the town square of Ponyville and all titles from the Princess.
Despite both having most of the dead come Back from the Dead following the defeat of the Big Bad, both the Dark World Arc and the Shining Armor Arc have some character's death's stick:
Dark World: Pinkie Pie, Fluttershy, Apple Bloom, Sweetie Belle, Big Macintosh, and Trixie stay dead due to dying because of age. Loose Canon reveals the same happened with Zecora, making them not eligible to accept the one time offer to come Back from the Dead.
Shining Armor Arc: Cool Sun, Shining and Twilight's uncle, stays dead as, according to his own spirit, he still died protecting Shining Armor with or without Makarov.
Sunset and Ranger are killed helping stop a megastorm threatening Caruba. We even see their funeral and their souls entering Pony Heaven.
The Killer in Me: Amnesiac type, with a twist. Stitches ended up spending most of her life running from Dark World!Fluttercruel as the Serial Killer hunted down and murdered her family, including her...It turns out she's Fluttercruel's future self, inserted into the timeline to become one of her own victims as an Ironic Hell punishment for her crimes.
Killer Rabbit: Princess Gaia's entire army is pretty much made out of these.
Kill the God: This is an extremely bad idea in this universe. The only way to kill a deity for good is by erasing them from existence, but doing so also destroys their Concept. IE, if you destroyed Celestia, the sun would not only no longer exist, but would have never existed at all. This is shown best by Cupid's demise. Which triggered a massive cataclysm that erased billions from existence. In addition D__t was erased because he wanted to Kill 'em All when it comes to the Gods. The CMC mention one of the worlds they traveled through was a dead universe ruled over by D__t, showing why he had to be erased.
Kitsune: Shining Armor's group ends up having one staying with them in Neighpon, constantly pranking them. However, because it's a white Kitsune, which are considered sacred and lucky, they just have to put up with it. Turns out it's the Empress of Neighpon's pet and was acting as their guardian on her behalf, catching some robbers that tried to break in.
Knight of Cerebus: Loneliness. Not only is she a genuinely terrifying character who tries to outright kill Twilight Sparkle, the Princess Gaia arc follows directly afterwards.
General-Admiral Makarov for Shining Armor's arc. Things took a turn for the serious as soon as he showed up, whereas before the arc was pretty light hearted minus an early appearance by the Wolf.
Nightmare Eclipse/Paradox manages to be this for Dark World, which was alreadyDarker and Edgier. When the story finally turns to her, it instantly becomes a WhamArc and the stakes go simply from freeing the world from Discord's tyranny, to having to save the entire timeline from being erased from existence due to her "Groundhog Day" Loop. Add in her rather frightening Faux Affably Evil personality and the fact she has the largest body count of any villain in the fic due to having gleefully erased the entire timeline and everyone in it several million times and she's most certainly this trope.
Queen Chrysalis for the main timeline.
Professor Kabuto serves as this for Misfit's (who have not yet met Queen Chrysalis personally) storyline at the wedding, due to being genuinely frightening and monstrous, as well as very dangerous and powerful, in contrast to the normal Changelings and the much more sympathetic Digger Wasp. Not only that, he comes quite close to killing them and is only defeated by Weaver performing a Heroic Sacrifice (she survives, but genuinely believed she wouldn't).
Last of Their Kind: The Dark World Mane Six (and Dinky) with the exception of Spike and Apple Pie are the last of the pure blooded ponies, the rest either gradually merging with another species (unicorns with Zebras, Pegasi with Griffins, and Earth Ponies with Donkeys) or being turned into the Sea Ponies or Dragons by Discord. To be specific, Twilight, Rarity, and Dinky are the last unicorns, Rainbow Dash and Derpy are the last pegasi, and Applejack and Pinkie Pie are the last pure Earth Ponies (the Earth Pony/Donkey hybrids still call themselves Earth Ponies, Apple Pie being one). Whether or not Fluttercruel counts is iffy, as she's half Draconequus and her original body is killed, then her second unicorn body transformed into a full Draconequus.
Due to Discord's genocides, the Dazzlings/Sirens are the last of the sea ponies, and barring Queen Rosedust also the last of the Flutterponies due to the inter-tribe spell they'd had put on them before the G2 Apocalypse mutated them. They're also the last surviving members of the G2 civilization. This fact makes Celestia hesitant to kill them, as she very much does not want to finish what Discord started by doing so.
Lord Tirek is the last Centaur. Because he killed all the others.
The survivors of the G3 World on Butterfly Island are faced with their world dying, a Reality WarperPhysical Goddess as their executioner. They decide to fight to the end anyway. Invoked by Strife, as it seems her intention was to enable them the chance to make one of these.
The Epilogue version of Cadence, having taken over the changelings and used them as a resistance force against Discord, is confronted by him and the discorded Mane Six, who destroy her refuge and kill many of her subjects. Cadence chooses to fight, giving her remaining subjects a chance to escape. And the sad thing is, she almost wins, defeating the Mane Six and restoring Twilight Sparkle... only for Discord to literally stab her in the back before disintegrating her.
Let's You and Him Fight: Subverted. It looks like the Dark World Twilight and Applejack are going to have a fight mistaking the other for still being evil, but they calmly work it out and join forces.
Ley Line: It turns out in the POV-verse, this world has nine lay lines, with three places where the lines converge: Everfree Forest (with the Castle of the Two Sisters as being the true convergent point), a location in the Griffon lands, and a third in the Deer homeland. Zebras, Minotaurs, and Deer are able to use the leylines to access knowledge about the world and other worlds due to the nature of their own magic. In 7 Dreams/Nightmares: Bright Eyes Zecora is able to gain knowledge of the G3 world is either due to her being close to the leylines, or because Ms. Hackney died at the exact time when the G3 world changed, thus her soul being in flux when the timeline changed.
Light is Not Good: Princess Gaia is an extremely beautiful Alicorn... Who is effectively brainwashing all of Equestria and turning everypony into little foals.
The Elements of Harmony, and by extension, the concept of Harmony itself, turns out that their power is inherently neutral, having the exact same effect on Celestia & Luna, possibly Zecora too, as Discord in one alternate timeline.
Living Lie Detector: After looking into the Truth, Applejack looking into ponies' eyes has this effect. She's the Element of Honesty so it really fits.
Load-Bearing Boss: The Redlight District implodes into Oblivion after it's victims are purified. Justified, as that was Nythy's trap.
Loads and Loads of Characters: The story involves so many background characters from the show, original characters, and even characters from previous generations of the franchise, that they get a greater net total of attention than the Mane Cast. Which makes sense, as a recurring phrase is "there are no minor characters".
So many characters get significant focus in the story that the character list had to be split into sub-pages.
Logical Weakness: The Concept Killing Spear will Ret Gone anything it pierces. However, it is still a spear, and it can't do anything to what it cannot pierce. In an alternate universe where Turris, the god of defense and barriers, saved Cupid, the weapon breaks against him.
This is basically an explicit superpower of Apple Pie in the Dark World, her Element of Laughter allowing her to manipulate or impede the flow of mana by invoking paradoxes. This allows her to do things like (accidentally) triggering a Heel Realization in Twilight Tragedy, destroy a zombie army simply by pointing out they can't be dead and alive at the same time, and (of course) make a giant-cyborg-spider-vampire's head (followed by its entire body) explode by pointing out how it's programmed to destroy harmony and protect chaos but half the group have BOTH sets of Elements inside them.
On the last one, Rarity and Twilight promptly lampshades the most common version of this tope.
Rarity: Why do paradoxes always make robots explode? Shutting them down I understand but exploding?
Invoking these is needed to break the Rumors curses during the Rumors Arc.
Long Lived: According to Word of God, Granny Smith is over two hundred years old and is the longest living pony in Equestria.
A few chapters are explicitly stated by Word of God to be "optional canon" and the readers are allowed to decide for themselves rather or not they're part of the canon or just interesting What If? situations.
Pinkie Pie's side story is even more so, to the point it can be even a completely different story if the readers so choose.
This may not be the case anymore, thanks to "The Foal of Omelas" chapter.
Lost Technology: Early on in the series, it was shown that the Canterlot museums had technology that seems that are so advanced that they look seem to come from our' (read humans). It turns out that the technology is from G2, whose technology had developed so far to become compatible to the human world. However, when they suffered a magical apocalypse when creating G3 world (AKA: Th Lost Age, Age of Dreams), their technology became regressed.
Magic Feather: Twilight realizes after she activated the Element Of Magic without the physical Element that all the physical Elements Of Harmony do is provide a medium for their power to flow through. Turns out friendship is just as good of a medium.
Magic Versus Science: Discussed in Clover's Gaiden Story by Twilight, Pinkie, Zecora, and Luna. The Earth Ponies of the golden age had forgotten of magic, despite having a near 20th century era technological society, while the Pegasi and Unicorns had extremely primitive technology, but had equally advanced civilizations based on their magics, and thus both were surprised to find it was possible for the other to exist (though subverted in that it didn't result in conflict). Luna praises the present civilization for having advanced both at the same rate and blended the two to result in a civilization that's in some ways superior to the Golden Age, if not as advanced. She also mentions Strife once set up a conflict between equally advanced civilizations, one based entirely on magic and the other on technology, and had Judicium, Concept of Judgment and Balance, decide who was correct in their assumption they were superior. Judicium judged that magic and science were equals, something Strife's experiment proved correct.
Make Way for the New Villains: Subverted in "Origins". While Discord does eat Havoc's Avatar, it was Cadence who actually mortally wounded him and Havoc's now completely insane Avatar let him do it, and its explicitly stated Discord is less dangerous than him due to only getting a faction of the Avatar's power since it was dying at the time. That and its debatable how much of a villain Havoc was.
Also subverted by Rancor in Dark World. While she did mortally wound Discord and steal Destruction's power from him, she had no intention of replacing him as the Big Bad. She just wanted to take Destruction's power so it could actually be used for it's proper purpose instead of for his sadistic games and just walks out of the story as soon as she gets it.
Princess Gaia's birds come to take away Dinky Doo as they've done with most of the other foals in Ponyville. Ditzy Doo (AKA Derpy Hooves) proceeds to grab a mop and use it as a quarterstaff to beat the living tar out of them for trying to get to her daughter.
It turns darker when Cheerilee, as Princess Gaia's Knight, is willing to use lethal force to keep the foals in her care safe and happy inside their Lotus Eater Machines. Princess Gaia herself later realizes the power of this trope and invites Ditzy Doo to become another Knight so she can extend that fierce protective instinct toward all of Princess Gaia's "little foals."
This seems to be Princess Gaia's policy now, at least in the Loose Canon. She extends her offer of knighthood to both Trixie and Twilight's mothers, trying to turn their maternal instincts to her benefit. Though we discover in "Playtime" that Ditzy didn't accept.
Do not harm or try to do anything to Pip if Luna will find out. Fluttershy and Fluttercruel find this out the hardway, even if she shows restraint.
Even though she's insane, Screw Ball/Golden Tiara breaks out of the insane asylum and kills a Timber Wolf and a Cockatrice with her bare hooves to try and get to Diamond Tiara when she realizes her daughter needs her.
Remember Mimic's Dying Moment of Awesome? She did it because she's Celestia and Luna's mortal mother and she was protecting them from Discord.
Exploited by Discord to make his earthly mother, Shady, into his loyal The Dragon. Unfortunately for him, she cared about him enough to see how far he had gone and finally help stop him.
Dark World!Fluttershy. Even though Fluttercruel tortured her in her own mind for five hundred years to the point she wanted to die just to end both her own torment and what Fluttercruel was doing to others, she still loves her daughter with all her heart (in part due to seeing that Fluttercruel honestly believed said torture was showing Fluttershy love). She helps her friends stop her for the same reasons as Shady did, then followed it up by going into the Draconequi domain and standing up to the Draconequi andHavoc to protect her. Havoc is so impressed by her actions he lets her take Fluttercruel with her for reconditioning.
A mortal pegasus though it would be a bright idea to kill the son of the Love Goddess Venus (who's concept includes maternal love). Venus proceeds to descend to the mortal plain in an Unstoppable Rage so great that the earth shakes and blow a heart-shaped hole through the pegasus' chest before she can even attack. Then reduce her house to a molten crater as a follow up. According to some legends of the even, she didn't stop there and had Pandora erase the mare's soul from existence or destroyed her identity and made her a new child to repay the one the mare killed. According to Celestia, the legend doesn't do justice to what Venus really did.
Celestia: For if a mortal mother's fury is terrible, imagine the wrath of a mother with the power of creation at her hooves.
Fluttercruel has a habit of throwing childish temper tantrums when she doesn't get her way. Then again, she is pretty much a newborn, something Fluttershy picked up on, causing her to treat her like a child whenever she does something wrong.
Fluttercruel: Shut up shut up! You don't know anything so stop spewing dragon fewmets like you know me or someone you met twice!
Fluttershy: Oh my my my, such language. We're going to have to clean that mouth out.
Another occurs when the group realizes Dark World!Pinkie Pie has been Secretly Dying since her redemption (though Applejack and Rarity more that the OTHERS found out). Even Odyne!Cruelty stops in her tracks from shock.
Happens in Misfit's portion of the Wedding Arc when Professor Kabuto injects himself with the potion that lets him go One-Winged Angel. Misfit because he'd proved dangerous already and the don't know what he just did, and the Interviewers (and possibly Weaver, Diver, and Bombardier) because they do know.
Mass Super-Empowering Event: Sort of. It's revealed that the G2 Apocalypse spread and enhanced the effect of the Rainbow of Light making animals near it more intelligent, granting groups of cows and other lifestock, as well as Griffons and Keylongs (which ultimately merged with the Griffon species over the centuries), sentience.
It also mutated the Dazzlings into the Sirens and gave them some of their powers.
Master of Illusion: Princess Gaia, aka Nightmare Whisper. She is called the Kindest of Lies after all.
Mayfly–December Romance: Referenced by Rarity in her Reharmonizing chapter; she knows about Spike's crush, but is afraid to address it because she knows that by the time he's an adult, she'll already be 'in a rocking chair'.
Subverted in Dark World. After a thousand years, Spike's an adult and Rarity hasn't aged a day thanks to her Element of Chaos, meaning once Rarity is free from Discord's control, there's nothing stopping them from hooking up. On top of that, since Rarity is immortal, Spike won't have to outlive her.
By the end of the Dark World arc Rarity becomes the Concept of the Mortal Realm! And she and Spike are now married and rulers of the new un-corrupt world.
Meaningful Echo: When ponies are praising Princess Gaia originally, it's because they're brainwashed. In the final chapter, Fluttershy is still praised as Princess Gaia by a lot of ponies her actions actually helped out of genuine love and respect.
Meanwhile, in the Future...: Played for Laughs in the Shining Armor Arc. Several times in Chapter 20, something Shining comments on will be accompanied by a cutaway to the present (Shining's future) dealing with it. Justified as Shining is living in San Dimas Time, so it really is happening 'meanwhile'.
Meaningful Rename: After her Heel–Face Turn, Trixie renames herself "the One and Only Trixie", which is what Twilight called her when she guided her to breaking free of Loneliness' clutches.
Played With with the Shadows of Existence merging with mortal ponies. The Shadows are only half a soul, so while the merger works it's not two full souls fusing together. And sometimes instead of making a new soul, it's the Light and Shadow of the original pony, in which case they recreate their original soul, though primarily molded by the Light's new Shadow.
Played straight with G3 Minty and Star Song. The former was created when Clover's wish resulted in her, her husband, and their son becoming a singular being in body and soul. The latter is the same, being the result of the Dazzlings (at the time all five of them) merging into one due to having the exact same, mutually exclusive collective wish. It's implied the same happened to others who wished for the same exact, mutually exclusive wish.
Midseason Upgrade: At the end of the Princess Gaia Arc, not only does Fluttercruel formally join the group with her own Element Of Kindness, the mane cast figures out how to channel the Elements of Harmony without the physical Elements themselves, which is not only much more convenient, it means someone stealing the Elements of Harmony won't work anymore.
Militaries Are Useless: Subverted in The Wedding Arc. Despite most of the Royal Guards being quickly taken out by Chrysalis's manipulations, the survivors quickly rally together and prove very effective in taking out key targets in Chrysalis's operation. Actually proving vital to Canterlot's liberation and Chrysalis's eventual defeat.
The Reset Button nature that has actually been going on in Dark World is this as well, with but timelines rather than ponies. Effectively making the inhabitants of those timelines even lower than mere statistics. However, while Nightmare Paradox and her Psycho Rangers see no harm in this (except Mirror), those that know of their actions In-Universe treat these crimes with the appropriate amount of horror.
Discord's corruption are portrayed thusly, having severe effects on all those he corrupted and leaving long lasting mental scars.
He's still using the supernatural type in order to manipulate Diamond Tiara into freeing him, all the while doing the mundane type by asking contridictory questions to keep her torn between rather she's right or wrong, being good or bad, and so on.
Mind Screw: The CMC, Spike, and Silver Spoon Time Travelers. They manage to jury-rig a time machine and travel to Generation 1, Generation 3, the real world, and sideways through time. As if that weren't enough, the G3 universe was Retgoned from time, meaning it no longer exists to travel to! Its stated they probably broke half the known laws of physics and (according to Doctor Whooves) several unknown ones!
The discussion in Shining Armor 13.5 about North and South Ponia, which even in universe is considered this and confuses all present.
In Shining Armor 15 Part 1, Shining Armor has a dream involving Pandora. Pandora is the Goddess of Imagination and Hallucinations, and her Realm reflects that, being a nonsensical labyrinth with imaginary creatures running all over the place. And Shining spends the entire dream on the ceiling.
The Final Battle of Dark World is between the mane cast and their potential evil future selves (though Pinkie and Fluttershy aren't present and Rarity's counterpart is absent).
The Final Battle of the Wedding Arc seems to be this: Princess Cadence vs Queen Cadenza (Alicorn!Chrysalis, who's Alicorn form is Cadence's Evil Twin due to the two being different halves of the original Cadenza) for the title of Changeling Queen.
Mirror World: In the Finale Arc, this is were Alicorn!Applejack, Razarro, and Starlight go to confront Dark World! Nightmare Dash and her other Nightmare friends to save the Interviewers and Shining Armor.
Misfit Mobilization Moment: During the Wedding Arc, Minuette (a dentist and one of the Master's regenerations), Twinkle Shine (a hair dresser), Lyra (a musician with a human fascination), Bon Bon (a candy maker), and Moth (a reformed Changeling terrified of her own species) end up discovering something is wrong, and formulate a plan to sneak into the castle to find out what's going on. Not only do they succeed, they free Moondancer from Chrysalis' mind control (scoring the heroes first victory in the arc), then resolve to do something about the impending invasion, joined soon after by Lemon Hearts.
Next chapter, Prince Blueblood and his fillyfriend Arcane Spell (a castle maid) even up finding somepony (namely Cadence, imprisoned by Queen Chrysalis) trapped underground. Their response is to bust down a crystal wall and then proceed to storm the Wedding Hall with Blueblood of all ponies being the one to lead.
Ironically, Misfit Actual also play a major role in fighting Chrysalis. Also counts as their team essentially consists of themselves and any able-bodied pony they can find, including the previously mentioned Blueblood and a group of triplets from a different part of the guard.
Missing Backblast: Averted during Shining and Dima's battle against Makarov's golden helicopter. Luckily, when Shining walks into the backblast of a rocket launcher, he has his shields up.
Later averted again by Hooviet Conscripts. They lack shielding of course.
Mood Whiplash: "Happy Cake Adventure" starts with a Stylistic Suck storybook style story told by Pinkie Pie. It ends with another dwelve into the end of the G3 universe.
The latest Dark World chapters are rather guilty of this as well. Given where it takes place, it's not all that surprising that any light moments invoke this.
The audio adaptation of the Reharmonized series usually ends on an optimistic note. Cue the ominous ending theme "He Watches, He Waits" that reminds us all of Discord's inevitable third coming.
Starlight's 7 Dreams/Nightmares chapter. Part one? Her discovering Paradise Estate with her friends and helping Bright Eyes make a plan to use the Rainbow of Light to make a utopia. Part 2? Begins with the end of the world and Starlight discovering she died in the explosion when Mortis comes for her.
Chapter 21 Part 2 of Shining Armor, while also dealing with Discord and having dark moments, seems to lighten up as the group has some R&R in some peaceful nations...then they end up having to stop a gigantic storm in Caruba, with hundreds if not thousands of lives on the line. And then, Sunset and Ranger die and the rest of the chapter is spent mourning the dead.
Moral Dissonance: The entire premise of the series is that the Mane Six, and indeed all of Equestria, are struggling to come to terms with what Discord's Mind Rape said about each of them. But when Luna mind rapes Fluttershy and Fluttercruel far, far more worse than anything than Discord ever did to them, she considers it fitting punishment, as do the Flutters. However, the Mane Cast gives her a mass Death Glare and Princess Celestia apologizes for her (not knowing what she did, but knowing she did something to make Fluttercruel terrified of her), implying Luna is merely acting on outdated morals from 1000 years ago.
Whether justified for Fluttershy's crime or not, it turns out Luna's punishment was very much an act of vengeance against Princess Gaia for trying to steal Pipsqueak from her, and it turns out Fluttershy has evolved into an Alicorn, thus Luna may have partly been judging her by Alicorn morality than mortal morality.
Mordor: Draco Island, where the two gods of Dragonkind, Queen Tiamat and Bahamut live, is apparently this to most species, though for Dragons it's obviously far more pleasant and Tiamat herself is generally nice.
More Than Mind Control: It's implied in "Teacher, Teacher" that Cheerilee was so broken by seeing how badly all the young ponies she teaches were broken by Discord that she willingly supports Princess Gaia's sending everyone to their Happy Place. While she was brainwashed to some degree, she does admit a part of her wanted to do it and Princess Gaia talked her into it largely.
Mugging the Monster: Fluttershy turned out to be far stronger than Fluttercruel ever expected and she ends up the one being browbeat into submission instead. Lucky for her Fluttershy is nice enough to share her body with her.
Invoked by Professor Kabuto, who made himself look like easy prey so whoever came after him would be taken off guard by his actual strength.
Tiamat, the Queen of the Dragons, has five heads. While each has it's own mind, they never fight though.
Musical World Hypotheses: The Alternate Universe variety, spontaneously bursting into song is treated as perfectly normal In-Universe to the point Twilight is somewhat confused when Celestia mentions this was the proper response to stress in previous ages, leaving Twilight wondering when it WASN'T normal. Also, Luna originally was going to do away with this during the Cosmic Retcon of the G3 universe, but Pinkie and Minty kicking her flank with a musical number changed her mind and she actually thanks Pinkie for doing so later.
Rarity's reaction to yelling at Sweetie Belle and nearly hitting Sweetie Belle with a sharp circlet, coming close enough to cut a few hairs in her mane, in a fit of rage.
Rarity: Reality came down on top of me like Luna's moon fallen from orbit. What had I done? WHAT HAD I DONE-?!
Fluttercruel's reaction when her attempt to teach Fluttershy about the crueler side of nature makes her be corrupted instead of helping her.
The denizens of Sunny Town have this reaction whenever Applejack's Living Lie Detector gaze forces them to remember their misdeed through Princess Gaia's spell.
Rainbow Dash's reaction to how her dealing with Discord's Sadistic Choice turned out.
This is basically the default reaction of the Dark World!Mane Six when they're redeemed, though for multiple reasons; Twilight for her actions as Tragedy, Applejack for believing Discord's lies for a thousand years, Rarity for her greed causing her to neglect Sweetie Belle to the point of forgetting she existed, Rainbow Dash for realizing Discord had lied and never ended to destroy Sky Ocean and Cloudsdale should she fail, and Pinkie Pie for her monstrous actions and possibly condemning some of her adopted foals to Hell with her teachings. Fluttercruel even gets one when her possessing Sparkler causes the Discording she was born with to be undone, allowing her to grow a conscience and realize not only were her actions wrong, but what Fluttershy had really been trying to tell her all those years.
Dark World!Applejack has this reaction shortly after Twilight gives her and the rest of the Dark World heroes (minus Apple Pie, who settled for Restrained Revenge, and Rainbow Dash, who isn't present) for beating up the dying and powerless Discord. It kicks in when Discord begs them to spare his nieces, Screwball and Diamond/Mad Tiara and she realizes he actually has reason to think they would. The rest have the same reaction eventually, but Applejack seems most effected by it.
Applejack: Don't ya be stupid! We'd never be savages like— (looks down and sees Discord's blood on her hooves)
Starlight has this reaction when she discovers that the "All Wishes Come True" spell would have broken reality.
All of Nightmare Eclipse's former Co-Dragons have this reaction when their memories are restored in the fake Ponyville they ended up in. In part because, if Rainbow's presumption is correct, their souls were purified by the six sets of Elements that defeated Eclipse but their bodies weren't, so now they're sane and well aware of every horrific sin they committed.
Mysterious Watcher: While the mane cast have met them repeatedly, the Interviewer(s) seem to be everywhere something is happening, just observing and documenting. The latest chapter reveals they somehow got their hooves on Razzaroo's Apocalyptic Log (which by all accounts shouldn't even exist anymore), which they give to Twilight Sparkle in The Stinger of that chapter.
Discord's third coming was slowly built up through the actions of Diamond Tiara's.
Dark World was built up through Vision Quests before the story finally returns to it.
Names to Run Away from Really Fast: Seems to be a natural part of being a Draconequi, who represent Nature's Fury. So far we've heard of Discord, Destruction/Disaster, Dispute/Strife, Pandora/Pandemonium, Havoc, and Entropy. Entropy is also commonly revered to as "Mother The-End-Of-All-Things" by her children. Pandemonium's birth name, Desire, is an Odd Name Out in a way.
Necessary Fail: In the Finale arc, Diamond Tiara's mother is shown that if she had never gone insane, she would have become Spoiled Rich from "Crusaders of the Lost Mark", since that tragedy helped humble her and teach her how important her family and friends are.
Fluttercruel honestly wanted to teach Fluttershy something important for her own good, to let her learn the cruel part of nature, it ends up corrupting her for real as opposed to being just brainwashed by Discord. Fluttercruel gets absolutely horrified realizing this.
She also gets Fluttershy, and herself, drunk, which Word of God admits may have had something to do with their behavior following and made Fluttershy more vulnerable to the darkness than she otherwise would be.
While it's Loose Canon, it's implied that the Mane Cast are, unknowingly, being manpulated into commanding Princess Gaia's army via a boardgame they're playing with Gaia herself. If this is believed, Rainbow Dash unwittingly guides Gaia's army into "Gaiafying" Gilda.
In the aftermath of a battle, your friend-suddenly-turned-enemy lays indefinitely helpless before your group. To help console each other on this tragedy and related circumstances, one mentions that it is not too late to restore or redeem this friend. If you think that taking matters into your own hooves and executing your petrified former friend, Discord, by pulverization is not a logical next step, you are smarter than Galaxia, whose deed costs her life, sets the stage for a 1000 years of tyranny, and worst of all, could have been easily avoided.
During the battle between the Dark World!Elements of Harmony and Discord's remaining minions, Spike has to choose between helping Rarity and Twilight, both of whom got separated from the main group while fighting Fluttercruel and Angry Pie (respectfully). He figures Rarity will need more help and goes after her; in fact, not only has Rarity by this point killed Fluttercruel, but Twilight ends up overpowered by Angry Pie, who rips out her Element and leaves her for dead.
Discord's corruption actually helps the Mane Cast overcome pre-existing problems with their psyches and improve for the better. It also helps Trixie discover she's the second Element Of Magic and join the group as a Sixth Ranger.
Not to mention the fact he made the other Sixth Ranger, Fluttercruel, in the first place!
No Honor Among Thieves: Discord abandons Nythy to his fate. Justified, as he was furious with him for nearly doing the same to Diamond Tiara earlier.
No-Holds-Barred Beatdown: The Valeyard gives a brief one to Dark World!Derpy in 'The Ultimate Foe' while having all the heroines disabled and (if nothing is done) slowly dying. It backfires when his focus on Derpy distracts him from the others, allowing them to counter his attack. This, along with everything else he did to her, drives her over the Rage Breaking Point and into Tranquil Fury, at which point she beats him to death (since his regeneration template had been destroyed, this means the Valeyard incarnation is Killed Off for Real).
'Angry-Cruel Love' has Angry Pie dish one out to Twilight, ending it by ripping her Element of Magic out.
'The Real Hoof Blues' has Proto-Nightmare Twilight deliver one to Angry Pie in revenge. It's so brutal the heroes have to step in to hold her back and when she's brought back to her senses, Twilight wonders how many times over she'd have killed Angry Pie if she weren't immortal.
No Immortal Inertia: When Liarjack breaks the curse on Epilogue!Applebloom, she instantly starts aging until she turns to dust. Of course, this was what Applebloom was wanting to happen, so she can finally die and be reunited with her family in the afterlife.
This is more or less General Admiral Makarov's response to anything.
No Medication for Me: According to Word of God, this caused some versions of Golden Tiara to go insane, but is subverted with the main one as she did't get medication until it was too late.
Discord apparently did this once.
No Name Given: Loneliness' never actually names herself, that's just what Twilight calls her and she doesn't seems too fond of it. What her real name, if she actually has one, is left open.
The Father of the Alicorns is never named. According to Word of God, His name can't be pronounced by mortals.
General Admiral Makarov's true form is never actually named outside of the Rebels nickname for it (the Shadow of Chernobull). This is because Pandora never got the chance to name him before he went berserk and even when she shows up, she simply calls him 'son,' 'junior,' or 'Nameless.'
Non Standard Game Over: When the CMC free the ponies trapped in the Redlight District, the whole place implodes into Oblivion and they receive a mocking message invoking this trope from Umbra Breeze.
Umbra Breeze]: [[spoiler:"Congratulations, You Have Uncovered A Hidden Death. Tis A Sad Thing, That Your Adventures Have Ended Here. Trophy Unlocked? Oblivion!"
Applejack mentions a rather crazy adventure Applebloom had when they visit Canterlot that somehow got the little filly temporarily turned into a Sea Pony.
The Cutie Mark Crusaders somehow managing to summon a fire elemental. Topped by them apparently having a spectacular time travel adventure that we only get tibits of.
The last time Twilight got drunk. Apparently, Ponyville had to be reassured Discord hadn't come back afterwards.
Luna's conflict with a revived Tirek for dominion over the night over 1000 years ago. All that's been revealed is the Rainbow Of Darkness brought him Back from the Dead, he fought Luna, and was defeated, after which Luna claimed his chariot as her own.
Celestia has mentioned in two different stories of cases were an assassin trying to kill her actually knocked on her bedroom door out of politeness.
The Dark World!Mane Cast tend to mention random crazy events at various points that have happened, such as a time when Discord flipped everypony's gender for awhile or that Rarigreed once had a Pony-Eating Rock for a pet until Angry Pie thought it laughed at her.
Shining Armor tends to mention events like this (given his Deadpan Snarker personality), such as a time he ended up accidentally getting having a misunderstanding with a Neighponese Samurai at a party leading to a drunk Neighponese Prince trying to start a fight with him.
Corporal Ellis Bitter Apple tends to tell stories to this effect, since we ultimately only get snippets.
In each of the Gaiden chapters, the pony narrating mentions an incident where Patch ate poisonous mushrooms, which was why they all had trouble believing her about Paradise Estate.
No Place for Me There: This seems to be the ultimate outcome of a Nightmare actually achieving their goal; a world were they themselves have no place, often due to the very crimes they caused to make it that way. Nightmare Mirror's world has no deceit, meaning she can't hide from the horrible crimes she committed did to achieve it and turns herself in to the Princesses. Nightmare Granfalloon (one of them, anyway) recreates a stable version of G3 by brainwashing everyone and rewriting reality, leaving only herself unchanged, at which point she turns the spell on herself and remakes herself into a copy of G3 Pinkie just like she did everyone else because there was no place for someone like her in it, and her friends wouldn't be happy without G3 Pinkie there with them.
Not Hyperbole: Shining sometimes has moments like this due to being a Weirdness Magnet, but one in particular is describing the Mammoth Tanks the Hooviets use.
Shining Armor: Ok, so we weren't dead, but we're going to have to fight against two tanks' who's schematics actually say 'designed to kill everything.' That was not sarcasm, they literally say that. Except in Roedinian.
Applejack's threat to have the unicorns turn Twilight into a filly so she could spank her if she does something stupid during her solo mission during the Wedding, turns out to be this.
Not Brainwashed: Twilight initially assumes that the New Fluttershy is just a discorded Fluttershy, this backfires when she uses the memory spell to no effect, instead receiving a headbutt to the face from an irate Fluttershy. Notably, it has failed both times that it has been used on her.
The Valeyard in Dark World is revealed to not be the Discorded Doctor, but instead a pure evil regeneration of him when Twilight tries the Memory Spell on him, only for him to No Sell it and nearly cause a copy of his personality to replicate over hers.
Not Quite Dead: As of the Finale Arc, turns out Nightmare Eclipse's Co-Dragons weren't destroyed upon their defeat but simply (somehow) lost their memories, living in a fake Ponyville. They've also had their souls purified, though their bodies weren't.
Nothing Is the Same Anymore: Shining Armor 18 has General Admiral Makarov erased from existence, altering the world Shining Armor, Minuette, and Cadence find themselves in considerably, including altering characters like Bond's entire personality and adding his now alive parents to the cast.
The Wedding Arc chapters "Orange Butterfly" and "Sisters" has this happen: Scootaloo learns to fly and earns her Cutie Mark. Sweetie Belle also seems to have learned some magic from Chrysalis while under her power.
Nothing Is Scarier: Loneliness is pretty much the queen of this trope. We don't know what she really is, what her true motivations are, or even how she came to be in the first place. Her true form, if she even has one is never revealed. And she's much scarier because of it.
One of her forms is suspiciously similar to a Draconequus like Discord. Then again that could be her taking inspiration from Twilight's imagination.
Shining Armor's Arc use multiple versions of this trope for Psychological Horror. Throughout the first part, strange things keep happening to Shining Armor but there's nothing logically there to cause trouble...then we find out he's being stalked by a nigh-unstoppable spectral wolf seeking to Ret Gone him and realize all those incidents were it. After Shining learns of it, his growing paranoia over it turns the arc into a type two, as it's never clear rather the wolf really is there or not. There's also the fact that at this point just what it really is and where it came from is unknown inuniverse and out.
There's also a bit of this from the fact that Makarov's true form has never been shown in details except for glimpses.
Bright Eyes' Gaiden chapter has a Type 3. Throughout the Nightmare part, Bright Eyes keeps getting the feeling of a malevolent presence there with her whenever she's emotionally vulnerable from guilt or fear. At the end, it turns out this wasn't just her fear of facing her past, but D___t's Shadow of Existence stalking her, waiting for a chance to steal her soul and infant Concept to reconstitute himself.
Not So Different: Trixie and Twilight turn out to have a lot more in common than either was aware of. Not only are they both Elements Of Magic, they were both pretty antisocial growing up, though for different reasons, and had to figure out what friendship really means. On a humorous note, Trixie reveals that she once cast the same "Want it Need It" spell that Twilight used in "Lesson Zero" on herself, with simular results, though she managed to hide out till she could figure out the counterspell and fix it herself.
Similarly, Rainbow Dash and Trixie have similiar defenses set-up, and Trixie accepting this and offering understanding when Dash confesses what really happened with Discord to her is used as a measure of how much she's grown.
In a rather bizare version, Applejack ends up having this with herself. To prevent herself from going Nightmare in the event this universe breaks off from the main one, she ends up meeting her Orangejack self and at first, they don't get along at all, but gradually discover how much they have in common, such as being hardworkers and how much they care about their family and loved ones. Then again, this was actually the point.
Dark World!Spike figures out this is what Discord was trying to do by removing the spell keeping his instincts under control, Discord was trying to prove they were the same, that they couldn't beat their base nature and be different from it. Spike proves him wrong. In an epic fashion
Dark World!Fluttercruel tries this on Rarity twice, first about her willingness to kill then with their respective mooks. Raritywill have none of it.
Likewise, a recurring theme is comparing Discord to the Nameless Passenger. Discord himself points out both of them have a long, well thought out plan that they have a Villainous Breakdown if it's foiled and both have a habit of trying to make someone else feel worse to make themselves feel better. Add to this the fact the Passenger is also a Manipulative Bitch with a knack for The Reason You Suck Speeches and is willing to do whatever she has to to get her way, and it becomes all too clear the Passenger is little different from Discord despite her hatred of him. This makes sense considering the strong implication the Passenger is someone who became She Who Fights Monsters.
It turns out the Passenger is actually Nightmare Paradox/Eclipse, and has become worse than Discord. And she realizes this when her parents restrain her to let the Bearers defeat her, the same way that Shady and Fluttershy did to Discord and Fluttercruel. She doesn't take this well.
Professor Kabuto tries this with Garnet, due to both being medical personae. Garnet does not like being compared to him.
Nuclear Nasty: While the blast wasn't nuclear, the G2 Apocalypse is more or less depicted as a magical nuclear holocaust. As a result, many of the mutations spawned from it can come off as this. Especially the Dazzlings, who were normal sea ponies before the blast mutated them into the powerful sirens they are in canon.
The Nudifier: When he was a baby, Spike received a slight magic surge from Twilight and ended up accidentally doing this to Shining Armor with his magic fire, sending his uniform to Princess Celestia.
#1 Dime: A particularly chilling subversion in the Bad Future; Twilight Tragedy notes having a strange obsession with a pair of potted plants, always feeling that it's of utmost importance to keep them watered and in the sun at all times. Why is this? Because they used to be her parents.
Offered the Crown: Happened to Celestia and Luna after defeating Discord the first time.
Offscreen Moment of Awesome: A repeatedly mentioned even was Luna fighting a resurrected Tirek for dominion over the night. She won and took his chariot as a prize, which was the one she used on Nightmare Night.
It's mentioned at the end of Clover's Gaiden story that Luna and Celestia had to defeat one of the Eldritch Abominations that escaped Tartarus in an unseen adventure. It's later shown in a Loose Canon story, which featured another one of these with the Guard defeating the cult that released it offscreen. Celestia also states events like this happen from time to time (as Shining Armor's story reveals, there's an actual protocol for calling in the Princesses), and the Mane Six are only actually summoned if the Elements of Harmony are required to defeat a threat.
Both Nightmare Whisper and the undead foal in her crystal heart have this reaction when Fluttercruel's Element of Kindness awakens.
Fluttercruel has this reaction when she accidentally reveals herself to Celestia, on account of being the "daughter" of Celestia's archenemy. Celestia nearly face hoofs in response, as she's really sick and tired of everypony being afraid of her when they first meet. Though her inner thoughts reveal she would have reacted on instinct had she not sensed Fluttercruel's Element Of Kindness.
Discord, in the past before he became an Evil Overlord, gets this when Luna drags him off to face his parents. Considering his father is the embodiment of mass destruction and one of his teeth is twice Discord's size, this is a pretty reasonable response.
In Bright Eyes' Gaiden story, Twilight and company have this reaction to realizing Zecora overheard all the stories. Thankfully, the Zebra has a belief in Reincarnation so she accepts the revelations rather easily.
The Interviewers have one when it turns out, for the same reason he's immune to Makarov's Charm Person ponies, their normal 'ponies don't realize their presence is strange' status doesn't work on Shining.
Oh My Gods!: Celestia and Luna's names are used like this. Except by them, who being the Physical Godesses everypony else does this too, say "our mother and father" or "our parents" instead.
Oh, No... Not Again!: In Dark World, Apple Computer is informed his children had to save somepony from pony-eating rocks. His reaction is simply to state in frustration that "Ah thought we got rid of those things."
In the Shining Armor Arc, Minuette has this reaction to Private Running Gag getting attacked by a cat, which is apparently a common occurrence.
When the Misfit Units and the Doctor end up being threatened by a group of Hooviets, this is Shining's reaction:
The Omnipotent: The Elders are this, being so immensely powerful that their sheer power alone would destroy the universe should they enter it personally rather than an Avatar. And Havoc said even an Avatar of his strong enough to defeat Discord would level Equestria's east coast just by manifesting. On a few occasions, they've shown the ability to alter what's considered reality with a word. Entropy is capable of erasing even deities from existence just by saying "You don't exist", and the other Elders are capable of easily willing themselves back into it should she do it to one of them, and small bit of Fauna Luster's power obliterated the Windigos as the Fires of Friendship. However, they are big supporters of free will, and this combined with the damage they could potentially cause, means they normally act from behind the scenes.
Once Is Not Enough: Twilight assumed that Loneliness had been destroyed when she used the Memory Spell on Trixie. She was wrong and ends up being impaled for it. It takes Trixie blowing Loneliness up twice in a row to permanently destroy her.
Defied by Bright Eyes who's Genre Savvy enough from watching horror films to be aware of this trope and impales Cruel Eyes/D___t's Shadow twice (the second time through the heart), then vertically bisects his head with enough force to leave her sword embedded in his chest, just to be sure.
Pinkie Pie does a heroic version during the Battle in the Center of the Mind with Angry Pie by merging with Pinkamena to become her G1 counterpart, Surprise. It's a lot more badass than it sounds.
Loneliness does this after Trixie's memories are restored, turning into a monstrous Mix-and-Match Critter (heavily similar to a draconequus). She takes on one final form after this, the Great and Powerful Trixie.
Another heroic example-when Discord's mind games finally break her, Luna turns back into Nightmare Moon...and the process causes her to remember how kindly her sister treated her Quirky Miniboss Squad, which allows Luna's personality to remain intact and in full control of her abilities as the Mare In The Moon.
Fluttershy of all ponies does the evil version in the second half of Fluttercruel's staring chapter, turning into an alicorn named Princess Gaia.
Cheerilee gets her own transformation as Princess Gaia's Knight.
It's implied that this happens to any pony that accepts a Princess' power (ie. Gaia's knights, Luna's guards, etc.).
And now, Gaia's been forced into it, after Applejack forced her to confront that she's lying to herself. Everyone, meet NightmareWhisper.
Princess Celestia is revealed to be able to do this (maybe), creating a giant fire monster modeled off Orion.
When Misfit Actual confronts Kabuto, he injects himself with a serum that transforms him into a giant centipede like creature.
Queen Chrysalis' predecessor Queen Cocoon also performed this trope, with Kabuto's being based off hers, due to him having been the one to alter her to allow it in the first place.
Abandon does this after Rarity is purified revealing his true formand shedding his Creepy Doll disguise. 'Spike' counters by revealing histrue form, a post Heel–Face Turn Nightmare Bannerette (the same one who had worked with Nightmare Eclipse).
General Admiral Makarov's true form is only known as the Shadow of Chernobull, a nickname the rebels seem to have given him. He actually doesn't have a name of his own because he went berserk before Pandora could give him one.
Zecora was able to shake off Discord's influence by herself, and Scootaloo managed to avoid being Discorded entirely.
Applejack's Living Lie Detector powers protect her from Princess Gaia's Lotus-Eater Machine, but she then awakes to find everypony else trapped in her illusion. The similarity to Twilight's situation when they were all Discorded doesn't escape her either.
O.O.C. Is Serious Business: For the readers, something seems wrong with Twilight when she starts acting like a Jerkass at a party at Canterlot Castle during what would seem at first glance to be her time before going to Ponyville. However, this is intentional, as a tip off about the nature of the current reality, since a few seconds later, she somehow finds herself talking to Smartie Pants.
A number of these happen during the Wedding Arc due to Chrysalis having brainwashed more ponies.
Invoking this trope is how the CMC free ponies from the Rumors curse: making them realize they're behaving out of character and causing the curse to die.
Opponent Switch: The Dark World!Mane Cast do this for their second fight with Paradox's Psycho Rangers with Derpy and the newly arrived and recharged Princesses fighting Nightmare Manacle, Applejack fighting Nightmare Whisper, Twilight taking on Nightmare Granfalloon, Apple Pie and Spike holding off Nightmare Mirror, Rarity battling Nightmare Banneret, and Ender Dash keeping Nightmare Paradox busy. While it doesn't make it a Curbstomp Battle, it evens the odds due to the new match ups countering the Nightmares' powers more effectively and ultimately forces Paradox to recall her Nightmares back into herself as opposed to the Curbstomp Battle the Nightmares dished out before.
Origins Episode: The Origins Arc serves as this for Discord, Celestia, and Luna as well as the Windigos.
'A Fading Future' explains the origins of Nightmare Eclipse/Paradox.
16.5 of the Shining Armor Arc is one for General Admiral Makarov. Or rather the backstory the Shadow of Chernobull made for him.
Origins: Queen Chrysalis serves as one for Chrysalis.
"The Birth of King Sombra" explains both Sombra's origins and how he and the Crystal Empire fit into the POV universe.
Wedding: Kabuto is partially this for Kabuto, explaining some of his backstory: he's the son of one of the Changeling's greatest Alchemists and bio-engineers who raised him to exceed himself. His father was evidently killed by one of his own creations going berserk. It also explains that he's well over a century old and artificially extended his life span.
'The Dazzlings' is this for...well, the Dazzlings/Sirens. They were sea ponies and somewhat friendly rival band to Melody's band the Rockin' Beats until the Apocalypse happened, mutating them into the sirens we see them as in canon and killing two of their band-mates and sisters. Now ostracized by society for either their monstrous appearance or their support of the Wish Spell, they manage to befriend the Rockin' Beats and survive together until a lynch mob attacks them. As the group is being brutalized, until Adagio awakens theirMagic Music, resulting in their Start of Darkness and them becoming the villainous sirens from canon.
A Rainbow Discovers the Truth turns out to be one for Nightmare Eclipse's Nightmare Manacle.
Tirek's Gaiden story "The History of Tirek" serves as this for him and the Moochick. And Ponykind itself, shocking how they gained sapience.
Sunset Shimmer got one, showing how she ended up as Celestia's apprentice.
Diamond Tiara and Silver Spoon. Though ironically, it's about them being happy as kids rather than a Start of Darkness.
Organic Technology: The Deer Rebels use magically grown fungus as the power supply for their vehicles.
Our Angels Are Different: Angels are described as being mortals who earned their wings with good works, mortals who took a burden after their death, or spirits made to serve as messengers between Concepts and Mortals. Only one Angel has been seen so far in the series, and that's Starlight, an Angel of Death, which seems to be of the second type. Considering Saint is shown to be a title given to mortals who did great things in life, it's possible that Sweet Heart and Dark World!Applebloom may qualify as well. Given Half-Light Noon's statement, they're apparently respected quite a bit.
Our Demons Are Different: General-Admiral Makarov/The Shadow of Chernobull is commonly called an 'Imagination Demon' but Mother Deer implied it wasn't the case but 'close enough'. The Shining Armor crew also apparently had a run in with a 'fear demon' somewhere in Zebrafrica, but this was a largely Noodle Incident. The creatures sealed in Tartarus are quite demonic in nature, but are actually entities from a destroyed universe.
Our Hero Is Dead: The G3 timeline ends with Strife killing most of the heroes (Minty and Princess Rarity being the only ones she doesn't kill directly). Though all of them are given Reincarnations in the new timeline in some form, as they weren't on the 'delete' list (Strife only did it to give them the chance to make a Last Stand instead of fading away with no chance to even try and save their world).
'Angry Cruel Love' ends with Dark World!Twilight having her Element ripped out by Angry Pie, being left to die of Rapid Aging and seemingly dying at Trixie's grave.
Our Souls Are Different: They're composed of two parts, a Light of Existence (the heart) and a Shadow of Existence (the appearance), both containing parts of the pony's personality. If erased from existence, the Shadow ends up in Entropy's Realm (what happens to the Light hasn't yet been stated). What's more, its stated that there's no 'Law of Conservation of Mass' when it comes to souls, meaning the same person can have multiplereincarnations (Dark World!Twilight being the reincarnation of G3 Minty's Light and Minty Pie being the reincarnation of her shadow, for example), but the soul will still exist independently of the reincarnation.
Our Titans Are Different: Titans in this universe are mortals who have the might and power of a god, but have not become true deities with the cosmic responsibility that comes with it. Lord Tirek, King Lavan, the Sirens, and Lilith the Witch Queen are all examples of Titans, being mortals who mutated into world threatening sapient cataclysms.
Out-Gambitted: Applejack's view of the Bad Future implies that version of Twilight manages to do this to Discord, simply by writing a letter to herself when she's briefly unbrainwashed, allowing her to regain her memories behind Discord's back and begin plotting his defeat.
Outscare the Enemy: During the Final Battle of the Age of Myths (G1), a group of goblins try to attack Paradise Estate...and run into the Crabnasties. They proceed to run away. Fast. Of course then one of Hydia's relatives Ashley scares them back into the battle right afterwards.
Button Mash from the Rumors Arc due to having gained video game Personality Powers thanks to various factors. The Rumors world is designed to run by horror movie rules, but he's running by video game rules. This makes him a valuable ally for the Crusaders, since he can fight monsters they'd struggle against head on to help them get to the person they need to save.
Daring Do during the same Arc. She's AK Yearing transformed into a real life Daring Do thanks to Pandora, meaning like Button Mash she runs on different rules and is able to better save ponies and aid the CMC. Justified as this was exactly what Pandora was going for.
Rainbow Dash transformed into the Mare-Do-Well, once more during Rumors. the Rainbow Factory rumor wasn't prepared for a comic book superheroine to show up and her Enemy Without has to cheat and pull out new powers out of nowhere just to keep up.
Nightmare Bannerette serves as this, as Abandon was illprepared to deal with him.
From Loose Canon (then Ascended Canon) Lovestruck, who was transformed into Cupid's successor and a Demi-Goddess with Venus' help. Her powers allow her to use her full power without being detected, allowing her to better save ponies without giving herself away.
In general, it seems every hero the Concepts set up to combat the Rumors was this trope. Justified, as with the world rewritten to run on horror movie rules, they NEEDED heroes who ran on different rules to keep people alive.
Princess Gaia. The group just went looking for Fluttershy and had no idea there was a new Big Bad on the loose. When they do find out, they have no idea what she's capable of, as her powers seem to exceed even the Princesses, or what her real plan is.
The Outer Concepts during the Rumors Arc, who no one saw coming.
Papa Wolf: Despite his Blue and Orange Morality, Havoc does genuinely love his family. Attack them unprovoked and you'd better hope the Alicorn Elders will protect you, because they're the only ones who can.
Teddy in Sweetheart's Gaiden story. Some corporate thugs are sent after Sweetheart to try and scare Starlight and compaining into stopping their project. Teddy may have ended up in the hospital, but so did the thugs. A pack of Simurghs attacks the family after the apocalypse. Teddy breaks one's neck while fighting to protect his family.
Shining Armor has this mentality towards both those under his command and innocent civilians. Harming any of those is going to clop him off.
Paper-Thin Disguise: Pretty much any time Cadence disguises herself in the Shining Armor arc except the time she sneaks along on the mission in Nambutu.
In Shining Armor 14, The SAS pose as "private security" for Equestrian archaeologists since Guards have legal restrictions on operating outside Equestria. Minuette and Twinkle Shine aren't fooled at all.
While they haven't outright abandoned her, the post "Sisterhooves Social" rewrite reveals their parents have a habit of dumping Sweetie Belle on Rarity all the time. According to Rarity, they do this so often that Rarity has Sweetie Belle in her care more often than their parents do. No wonder Sweetie Belle loves Rarity so much...
Parents as People: Given the focus on characters in general, most parents who appear are portrayed as this naturally.
Persona Non Grata: After his attack on Shining Armor, Makarov is threatened with this (in multiple countries) in order to keep him from trying anything again... for now.
Physical Goddess: The Princesses, as to be expected. All three of them. In fact, Princess Gaia may be even more powerful than the other two combined. We find out later there used to be 13 of them. The Draconequi also qualify
Playing the Victim Card: Fairly common among the villains. Mainly due to most of them using it as a justification for their misdeeds rather than accept responsibility for their actions. It's notable that a large number of the inmates in Hell do this when seen, which is implied to be part of why they're stuck there: they refuse to accept that they're the only one responsible for their own evil.
Plot Twist: Who actually realized Onyx Tiara was partially discorded at the start of Mind Games part 2?
Police Are Useless: Subverted. The Guard is actually quite competent at dealing with most threats that don't require the Elements of Harmony to defeat, and even assist the Princesses in defeating a Eldritch Abominations on occasion according to Loose Canon. This is best shown in the Shining Armor Arc, which focuses heavily on them.
Pony All Along: The Changelings aren't a separate species but a fourth Pony tribe. Even the Changelings themselves weren't aware of this.
Ponies Are Flawed: A reccuring theme in the story is everypony, even Celestia and Luna who are literally considered goddesses (even by themselves), aren't perfect. The only ponies who ever were are Celestia and Luna's parents.
Princess Celestia tells Pinkie and Applejack that this is one of the things that they, and everypony else, have a hard time accepting. She explains that, instead of accepting this, ponies try to rationalize or justify their bad decisions — which is one of the most dangerous thing that they can do. This is a lesson Pinkie must learn to help prevent her Sanity Slippage when the POV timeline breaks off from the canon timeline.
Far Sigh, one of Nightmare Moon's lieutenants/friends and implied ancestor to Fluttershy revealed in the "Canterlot Chaos" side story, was born of a pegasus mother and a dragon father. Other ponies reacted negatively to the union.
Ponyville Is The Center Of The Universe: The Loose Canon Coffee Swirl series arguably deconstructs this; thanks to the constant crossfire his town is caught in with the Elements of Harmony living there, the titular pony has developed a lot of mental issues and is convinced that his life is completely outside of his control.
In the main series its deconstructed as well, as the state of disrepair Ponyville was in in "The Mysterious Mare Do Well" are revealed to be because Ponyville blew through its repair budge due to all the disasters.
Averted in Shining Armor's Arc, where it's just Shining Armor that seems to be running into all variety of bizarre events and situations no matter where in the world he is at the time.
Posthumous Character: With the exception of Pinkie Pie, Star Catcher, and Sky Wishes, the hero cast of the G3 stories are dead long before the story starts and its told via flashbacks by Pinkie Pie. Though some of them do have Reincarnations in the main timeline.
Starlight in the Nightmare portions of 7 Dreams/Nightmares Side Stories, as she's killed in the explosion that caused the collapse of the G2 society. Including her own.
Post-Script Season: The Discorded Pony POV series starts out as an anthology of the Ponies POV after being Discorded, then the Reharmonized develops another anthology from the canon of the Discorded material. Once Trixie is fixed up, a narrative starts to form setting up that Discord is coming back for round two, and it breaks completely into serial form when Princess Gaia shows up. This is interesting because the writer originally wanted to stop with Epilogue, but decided to do the Reharmonizing Series... Which in turn was decided to end with Rainbow Dash's reharmonizing, but ideas just kept coming until the writer has had to literally force themselves to settle for an exact ending.
Powered by a Forsaken Child: Fluttershy's ideal paradise where everyone is happy and carefree is powered by Fluttershy herself turning into Nightmare Whisper and absorbing every bit of pain, every bit of anger, or sadness, of any negative emotion into her own self. That's right, all the suffering of the entirety of Equestria, stacked on one single pony. She explicitely refers to herself as "Forsaken Foal of Omelas", in reference to Ursula Le Guin's iconic short story.
Many of Makarov's weapons are powered by unicorn horns. The allies also fear he's also using his prisoners to power his Skyfall weapon though that turns out to not be the case.
A given, considering what fandom this is for. Its even stated that Trixie had just as much potential as Twilight does and is even a second Element Of Magic, but because Friendship Is Magic, she was holding herself back by refusing to make friends. She gets better in the end though.
During the Final Battle with Nightmare Whisper, the group's friendship and desire to save their friends acts as a medium for the Elements Of Harmony, allowing them to use them without the physical Elements.
The Power of Love: Shows up in the Wedding Arc, naturally. While the Changelings use it as a food source, it's revealed that showing true love to a brainwashed victim while aware they're brainwashed is the key to breaking their mind control.
Familial love is later used to free Applejack by Applebloom. They then use the familial love of the Apple Family to supercharge Applejack's truth vision and obliterate one of Chrysalis' self deceptions (namely that her past is dead), leaving her writhing on the floor in agony, letting them escape.
The Centaur Empire, which was once the biggest and most advanced Empire in it's heyday and predated Ponykind as a sapient species. Sadly, Lord Tirek is the Sole Survivor of the Empire because he destroyed it, and he is most certainly an Abusive Precursor. The Empire as a whole may count as Benevolent Precursors to a degree, as they treated the then nonsapient Ponies fairly well.
The Age of Myths was this to the Age of Wonders, being all of G1. The Paradise Estate Ponies in particular count as Benevolent Precursors, as they actively defended Ponyland from any threats that may come up, including defeating Grogar every five hundred years if they couldn't keep him locked up.
The Age of Wonders was this to the current age being the My Little Pony Tales society, until it was destroyed by a Class 2 Apocalypse. To a degree qualifies as Benevolent Precursors, as some of them genuinely DID try to make the future brighter for the civilization to succeed them. Also count as Benevolent Precursors to the Lost Age, which they used their wish spell to create.
Precision F-Strike: Makarov wanted to hear "I surrender, Solomon" from Shining. He got "Go fuck yourself". Notable for being the actual f-word, not buck, because it's aimed at a male half-deer.
Generational Transitions as well, which chronicles the end of the G3 universe.
7 Dreams/Nightmares Gaiden is another, detailing the end of the Second Age of Pony civilization.
The Shining Armor Arc is this, detailing events starting as early as the first episode of the TV series. Subverted in that it turns out due to Shining being Immune to Fate, San Dimas Time is in effect and it's be happening alongside the rest of the series rather than before it.
Psychic Static: The Rebels that Shining encounters mentally recite everything as if they were Hooviets as a precaution in case Makarov manages to get in their heads. This is why all segments from their perspective appeared to be Hooviets.
Dark World!Fluttercruel big time. She's the only one of Discord's minions to actually enjoy what he orders her to do and gets a big kick out of killing people.
The League of Auxiliary Minions could also count, considering the glee they take in doing wrong the one time we see them. Justified, as one of Shining's hallucinations implies Discord made them from Dark World!Makarov.
General-Admiral Makarov is a iffy example. On one hand, he's an utter psychopath who enjoys the horrific things he does for the Hooviet Empire. On the other, he's actually the one pulling the strings and in fact the only reason the Empire was still afloat at all, so the 'For Hire' part is questionable.
Professor Kabuto is this for the Changelings. While most Changelings don't take active sadistic pleasure in what they do and are merely doing what they, wrongly, believe is needed for the well being of the swarm, Kabuto is a psychopath who enjoys performing sadistic medical and scientific experiments on innocent creatures (including his own species). He's so psychotic that even the other Changelings hate and fear him.
Psychotic Fillymare: "Psycho" is a stretch, but it's quite clear that Princess Gaia is rather childlike, even throwing a tantrum when she doesn't get her way.
Dark World Fluttercruel is much more clear cut on the "psycho" part — when she throws a temper tantrum, ponies die badly.
General-Admiral Makarov is a Type C. He's extremely powerful both literally and figuratively, but also extremely childish and spiteful, throwing a temper tantrum any time he doesn't get his way. This in some ways makes him more dangerous because he's willing to kill someone just for getting his name wrong.
Queen Chrysalis also counts as a mix of Type B and Type C, but she's considerably more downplayed than the others. She is legitimately powerful and intelligent and having an absolutely horrific long term goal, she's also driven by her foalhood desire to conquer Equestria, and while occupying Canterlot treats her slaves more like a child playing dollhouse than a conqueror, and overall seems to have not thought out or cared about what she'd actually do with her new power while waiting for her main plan to reach completion other than whatever she feels like. In this case, it adds a sense of wrongness to her character that helps sell the fact something is seriously messed up with the Queen.
The Dazzlings/Sirens seem to be this to the Princesses. Not only do they use Evil Knockoff versions of the Elements of Chaos in contrast to their Elements of Harmony and are sisters, as Sonata points out they're a twisted version of the idea the Princesses represent. Whereas the Princesses use their power, admiration, and fame to inspire ponies to become stronger, the Sirens use theirs to dominate, control, and make themselves adored. During their confrontations, the Sirens are also shown to be the Princesses equals or possibly betters in combat due to the amount of power they'd obtained by that time, and their artificial Elements of Chaos are able to counter the Princesses Elements of Harmony.
Punch Clock Villain: Well, Punch Clock Hero Antagonist, but Anarchy still qualifies. He's just doing his job and really wants to get it overwith. He even says that he'd be the first one to suggest a better solution, simply because a full Cosmic Retcon is way too much work.
Rancor in Dark World. She's literally only in conflict with the antagonists because Her Parents ordered her to help her big brother Discord out and when its not her turn to fight the heroes, she has absolutely no animosity towards them (ironic considering she's the Anthropomorphic Personification of animosity) and is downright friendly, even asking Rarity for her autograph because she was Melody in a past life. She is a Blood Knight and enjoys fighting, but its Nothing Personal, just her job. When she completes her actual mission, namely stealing Destruction's power back from Discord, she bids them farewell and heads back to Oblivion to a party in her honor and admits in comments that she has no interest in coming back.
There's also Dark World!Discord's Magnificent 300 Goblin Cowboy Samurai. They outright say its Nothing Personal, they're just contracted to Discord and thus have to follow his orders out of honor. The moment said contract expires, they leave peacefully since...well, they don't like Discord any better than the heroes do but it'd be dishonorable to help fight him.
Put on a Bus: Trixie, at the transition between the Princess Gaia and Butterflies arcs, bids farewell to the heroes and heads back to her hometown, removing herself from the plot for the forseeable future.
Dark World!Rainbow Dash is left at Sweet Rock Acres after her Heel–Face Turn because, due to her Heel Realization, she's presently suicidal and needs time to get her mind in order. She returns later on just in time to help the group take down Odyne!Cruelty. She and the Princesses are Put On The Bus after the latter are freed because the Princesses are presently powerless fillies, and Twilight doesn't want to put all their eggs in one basket on the off chance Discord had one last trump card up his sleeve.