Twilight in "The Mare In The Moon", as she sees the prediction of Nightmare Moon's return unfolding before her, knowing exactly what is going to happen and being powerless to do anything to stop it. Just how scared and nervous she looks makes it hard not to feel sorry for her.
Elements of Harmony
What happened earlier after Nightmare Moon shatters the Elements Of Harmony, the only thing capable of stopping her, right in front of Twilight Sparkle then gives her a Breaking Speech. The look on Twilight's face makes it clear that, until she realizes that her friends are what she needs, she's crossed the Despair Event Horizon. Thank goodness her friends showed up.
Luna. Just Luna. Nightmare Moon looked like Celestia, only dark and evil. Then we see that she was in fact this small Alicorn (she doesn't seem to be bigger than Twilight). Is just for a second, but seeing her almost cowering when Celestia gets close and then crying "I'm so sorry! I missed you so much!" just makes this troper cry (Because then you start to think that she stayed in the Moon for a thousand years. All. By. Herself.)
Rainbow Dash in the end when Gilda loses it. All she wanted was for her old friend and her new friends to get along, and look what happened.
Though a subtle example, when Snips and Snails talk about the most powerful pony in all Equestria, Twilight Sparkle is visibly bummed out, having been commended by Spike so much about her evolving magic, she seems disappointed to realize she isn't special.
Look Before You Sleep
It's kind of subtle, but Twilight Sparkle, who is effectively an adult pony, has never had a sleepover in her entire life. It really underscores how lonely her childhood must have been. No wonder she almost loses it when the sleepover comes close to being ruined by her friends' squabbling.
Word of God states that the Mane Six are intended to be roughly between 12-18 at the start of the series... but it's still rather sad. You can only imagine how she probably struggled with making many friends as a filly due to her being both a bookworm and Super OCD, among other things. It makes her initial attitude in the two-part opener look sadder — she's been so used to not having friends that she can't even understand how wonderful a feeling it is. All those people who grew up as loners (generally a combination of intended and not) can certainly relate — even if you claim you don't want to socialise, chances are you crave some measure of connection with others...
Swarm of the Century
Yeah, sure it's a minor background gag... but I really think you have to be completely unfeeling if you don't even have the slightest urge to give Lyra a huge hug after seeing the face she makes when she starts crying◊ after her cake gets eaten right in front of her.
Winter Wrap Up
From "Winter Wrap Up", Twilight's dejected face after Applejack lectures her for the trouble she caused with her poorly thought-out use of magic, followed by poor Twilight running away crying.
Call of the Cutie
Apple Bloom being teased for being a "blank flank". Anyone who has been bullied for being different than the rest of the crowd can easily relate to her. And then there's this face◊ that she makes...
Season 1 - Part 2
Suited for Success
Rarity's excitement at the first dresses she made in Suited For Success. It would be adorable and heartwarming, but her friends are just too disappointed by them to make it go how it should.
On the other hand, while Rarity's breakdown is considered to be one of her funniest moments, to some fans her breakdown is heartbreaking.
A Bird in the Hoof
"A Bird in the Hoof": Fluttershy's little whimper as she starts to cry and the face she makes◊ when Philomena bursts into flames, with her ashes slipping through Fluttershy's hooves. That scene had to be traumatic for some kids initially. They don't explicitly say it, but Philomena died.
It's not only traumatizing, it's also very depressing, both for the viewer as for Fluttershy herself. She had done everything to cure the phoenix, and it just combusts in mid-air. For Fluttershy, all her work would be for non. Plus, she's afraid since this is Celestia's bird, so for Fluttershy, she would think that she would be executed or something like that. Twilight's fear for the princess hadn't helped a thing in here, it only made it worse!
Cutie Mark Chronicles
In "The Cutie Mark Chronicles", the homesick Applejack's sad little "cock-a-doodle-doo" at the sunrise before shedding a Single Tear.
When Big Macintosh cried when Applejack left. It was so unexpected, but it underscored the fact that he's Applejack's big brother.
Twilight's slumped posture and defeated tone when she says "I'm sorry I wasted your time" to the examiners.
"There was no talking. There was no smiling. (sigh) There were only rocks."
Fluttershy being bullied by a pair of jocks who, while they appear younger, are bigger and stronger than her. Especially since she's only at Summer Flight Camp to get stronger, but she can't. Thankfully, Rainbow Dash comes to Fluttershy's aid and defends her from the bullies.
Owl's Well That Ends Well
Spike crying as he gets it into his head that Twilight doesn't love him anymore.
His whole self-imposed exile afterward, when he stays alone in a treasure cave and then almost gets eaten by another dragon, who was living alone in that treasure cave.
What about his state of envy leading up to that? He'd been going out of his way helping set things up for Twilight and her friends beforehand, and his obvious enjoyment of the attention he gets from said girls at get-togethers made clear that he felt it was worth it. Then some owl comes along to do the same thing and most of that attention, for a while, seems to be going to the owl. Spike even sees Rarity give the owl the same gift she gave him. As wrong as it was to react the way he did, it's difficult not to pity him.
And of course it becomes even worse after seeing "The Crystal Empire."
Party of One
In "Party of One", Pinkie's reaction when Spike tells her exactly what she wants to hear: that her friends are all lying to her and avoiding her because they don't like her parties and don't want to be her friends anymore. She's at first elated from being "right", but then the implications sink in. Pinkie Pie doesn't just get sad. She practically shatters. Just looking at Pinkie really sad for the first time is soul crushing.◊
Then, someone made this, to really drive the feelings home.
It's subtle, but this moment implies that Pinkie Pie hates being left all alone after one of her parties is over. The fact that she immediately tries to get another party going the next morning can easily be interpreted as her being desperate for companionship.
The Best Night Ever
The ponies finding the Grand Galloping Gala to fall far short of their hopeful expectations. What really sells the scene is that slow, sad music that creeps up during the montage. The musical number just before also adds to the weight of this whole scene, showing how much all six ponies have banked so many of their hopes and dreams on this one night.
Seeing Pinkie Pie, of all ponies, sitting alone and miserable, singing to herself, with her voice uncharacteristically flat.
Pinkie Pie:I'm at the Grand Galloping Gala... and it's not what I dreamed.
Rainbow Dash is finally invited to hang out with her idols, Soarin' and Spitfire, who despite being genuinely interested in her, end up getting snatched away by Canterlot's elite because of their fame. All the poor mare wanted was to spend time with her heroes and yet they were just pulled away from her because of a bunch of stuck-up aristocrats, leaving poor Dash heartbroken and out of the scene.
Applejack really wanted to sell out her apple desserts. But, needless to say, no one thinks to even look at them — or try them.
Fluttershy. She came across so many magnificent animals in the Gala's gardens. But, whenever she tries to interact with them, they always seem to avoid her.
Rarity. From her portion of the "At The Gala" song, you can tell she's absolutely overjoyed at the possibility of finding herself a classy coltfriend, only to have reality kick her in the face when she finds out the one she has her eye on is a total prick. She just wanted to be treated like a lady.
Judging by how excited he was to go in the "The Ticket Master", because he wanted to spend time with his friends, Spike spending most of the night alone at the bar makes you want to hug the little guy.
Twilight's story is also very sad. Watching the full episode, then going back and hearing Twilight happily singing, "It is going to be so special, as she takes time just for me!" She just wanted to spend time with her mentor.
Special mention goes to Pinkie Pie for how viciously Discord deals with her. Before her one-on-one meeting with Discord, she is happily trying to make the best of a bad situation and at times even enjoying herself. Afterwards, she spits out the word "happy" like there is nothing she hates more and is angry at the very idea that anyone is laughing in her presence.
Also there's the scene right after Fluttershy is brainwashed. She mocks Twilight, makes fun of her about not having her horn, slaps Twilight with her tail, and then walks away with an evil smirk on her face. The expression Twilight makes as Fluttershy walks away is just heartbreaking.
The way Rainbow Dash is broken. "Cloudsdale... Crumbles... Without me..."
Made even worse when you realize it's not just that her hometown is at risk of being destroyed. She's pretty much being forced to choose between helping her friends out of a life or death situation or saving her hometown from destruction. She has to choose rather to betray her friends or watch her hometown be destroyed and there's no viable third option in sight. And after what happened to Fluttershy, we know it doesn't matter if she finds one anyway, Discord will just Mind Rape her if she does. Dash is also the Element of Loyalty. It's not just the choice—it's that no matter what she does, she's betraying someone's trust.
Don't forget Twilight. Discord opens a path to her friends seconds after they've been broken by him, supposedly for the sole purpose of letting her see what he's done. She has to see her friends turn upon her one by one, becoming twisted inversions of the ones she's known and loved for over a year. Discord could do the same to her, with a Hannibal Lecture or outright Mind Rape like Fluttershy, but it seems he finds it more "fun" to twist the knife and let her suffer... and finally break all on her own.
On a completely different note, the reveal that Celestia and Luna once wielded the Elements Of Harmony together against Discord, proving they were really close back then... only for Luna to turn into Nightmare Moon and force Celestia to use them against her.
The Return of Harmony, Part 2
Twilight having to deal with all her "Discorded" friends. Again, having to watch the friends Twilight has known and loved throughout the last season become Jerkasses is really heartbreaking. And if that wasn't enough when they finally try to use the elements on Discord, it fails, and when everyone leaves Twilight sheds a tear that forms a broken heart as she too loses her colors.
The pain Spike endures returning Twilight's letters en masse is heartbreaking, especially in the circumstances. He's literally bedridden from it and is still sending them against his will, experiencing pain each time and his Cool Big Sis/Parental Substitute figure is almost too busy to notice... and the most heartwrenching part is that nobody had any choice in the matter, as the world would have been doomed if they did things any other way.
The vision Applejack saw back in the last episode before Discord worked his magic, ends up actually coming true here, with the Mane 6 splitting... heartbreaking.
It's initially more creepy than sad, but a lot of Twilight Sparkle's breakdown counts—the bit where she thinks Celestia will disown her for being tardy, the way she seems to view her Smartypants doll as something worthy of losing/fighting a friend over, and especially her mistaking a random bunch of laughing fillies as maliciously mocking her with horrible grins on their faces. It gets worse when you realize most of her visions involve being sent back to Canterlot away from her friends. Her Sanity Slippage makes a lot more sense, and is a lot sadder, when you realize she's probably terrified of losing her friends. Also, consider how a socially awkward pony like her would have been treated in school, especially given that she's gifted enough in magic to stand out from the crowd? Her nightmare vision of being sent back includes being laughed at by the other fillies, what if she's not imagining that, but is re-living it from memory?
When Celestia appears amidst the chaos at sundown and pulls a Full Name Ultimatum complete with an ominous echo. Especially since right after this, Twilight's comedic insanity is replaced by solemn, lucid defeat, quietly saying goodbye to all her friends.
The sheer fact that Twilight's friends pull an epic Big Damn Heroes moment to save Twilight from being possibly punished by Princess Celestia moved many fans. Considering that they are willing to defy their ruler (a Physical Goddess) to protect their friend shows how powerful their friendship has become all this time. Pinkie Pie nuzzling Twilight really hits home in this scenario. Twilight hugging Spike in the end also makes this moment powerful.
Spike's concern over Twilight, though snarky and comical at first, becomes rather poignant later on. Especially as he nervously watches Celestia confronting Twilight behind a bookshelf. He quickly attempts to keep out Twilight's vision after the princess informs her that it was him that asked for her to come, likely nervous about interfering with Twilight's personal conflict, however she quickly corrects this without words, and just grabs and hugs him, complete with Puppy-Dog Eyes.
Luna's final "How... about now?" at last spoken at a normal volume certainly tugs at some heartstrings. Without the extremely hammy voice, Luna simply sounds so young and even vulnerable, briefly showcasing how unsure she is in this episode.
The moment when Luna recognizes Twilight Sparkle. The memory of being saved by Twilight obviously had not left her (even if she has trouble getting across that she still thinks it a good thing).
Seeing Luna all depressed at the fact that everyone is so scared of her when all she really wants is to make friends is really sad. When she speaks near the end, asking Twilight to leave her alone in her sadness, you can practically hear her on the verge of tears. Poor Luna.
Especially if you remember one of the things that turned her into Nightmare Moon in the first place.
"It is of no use, Twilight Sparkle. They have never liked us. And they never shall."
Not only is she being rejected now, but one of the reasons she became Nightmare Moon was also that the citizens of Equestria hid and slept during the night while they played during the day. She makes her first public appearance since her restoration, likely out of curiosity that the ponies appear to be having fun during a nighttime celebration, only to discover that the holiday is celebrating her defeat and portraying her as a monster who wants to devour her subjects. As Luna herself declares when canceling it for the future, Nightmare Night is a complete slap in the face to her.
The shattered reactions to Luna getting fed up with being treated like crap and canceling Nightmare Night, especially that one filly who sobs about wanting to be a zombie next year.
At the end where Pip nuzzles Princess Luna after he gives her some of his candy and calls her his "favorite princess". Happy tears. Definitely happy tears.
The way Luna at first dismisses the ponies gives off a huffy "fine, I didn't really want to see you anyway!" vibe. Then Twilight follows her and finds her sitting in front of the Nightmare Moon statue, sadly offering a piece of candy. It's a small moment, but the expression on her face really does reveal how really Not so Above It All she was.
When Rarity sees the arts & crafts project Sweetie Belle made for her: a crayon drawing of them surrounded by a heart made of gems. Made worse by the fact that when Rarity first saw it she responded by shouting at Sweetie Belle for using the gems she had been saving, even claiming she wished she didn't even have a sister. Her My God, What Have I Done? moment when we finally see the picture is extremely powerful stuff.
The hurt look on Sweetie Belle's face when Rarity rejects her offer to take part in the social, calling it uncouth. She almost isn't able to hold back her tears. Likewise, Rarity's pained expression when Sweetie Belle rejects her apology and continues to disown her. If you look closely during their first argument, it's obvious that both Sweetie Belle and Rarity are trying to hold back tears.
Poor Sweetie Belle is a Woobie throughout, since she just wants to make her sister happy, but Rarity doesn't realize her good intentions are more important than the messes she causes.
The Cutie Pox
The look on Applejack's face at what was happening to Apple Bloom for the first time. It looked like she was about to cry.
Apple Bloom's depression after her failure at bowling, insisting that nothing will cheer her up, and wandering into the Everfree Forest.
Seeing the tortoise comes in last place in every competition, when he's so eager to get picked as Rainbow Dash's pet. And the falcon having to give up the race despite getting first place.
If Rainbow Dash getting one of her wings getting pinned down by a boulder won't get you, then her Single Tear at the thought of being trapped in the valley forever will.
Same counts when she is wailing after thinking that there is no hope for her anymore.
Rainbow Dash: I'm doomed. Doomed I tell ya! (cries silently)
At the start. Who hasn't felt left out because they didn't have something that all your friends did have?
Especially when the way Pinkie described it unintentionally made it sound like they were deliberately trying to exclude Rainbow Dash. Ouch.
Spike's reaction when it kicks in that Rainbow Dash was caught in the avalanche.
The Mysterious Mare Do Well
Even though Rainbow Dash was being taught a lesson by the Mare Do Well, aka The other Mane 5 there are times where you couldn't help but feel sorry for her, especially when she becomes so desperate for attention that she goes so far as to help Granny Smith cross the street when she didn't want it, to struggling to open a jar of peanut butter and mowing the grass.
At one point, the Mane Six are discussing the Mare Do Well (or rather, most of them are, while Dash is ignoring them), and soon the topic turns to Rainbow Dash. After Dash gets frustrated with Spike, who is misquoting everything she says while writing, the other five ponies start laughing. For at least a few seconds, it seems that Dash's friends are actually laughing at her and making fun of her. And, as we see later on, she really doesn't like being alone.
Sort of a Fridge Tear Jerker. Rainbow Dash resort to confronting the Mysterious Mare Do Well and exposing her in front of the entire town. And then when she runs she chases after her. Rainbow Dash would get a lot of grief for running the hero out of town and considering her friends weren't helping her through her depression and Ponyville was annoyed with her this could be the final straw. There's a good Rainbow Dash was aware of this and if she was that meant this experience was so painful for her she felt she had nothing to lose by pursuing the Mare Do Well.
When Rainbow Dash said that she hates being alone, she sounds like she's about to cry.
Sweet and Elite
Rarity tearing up after Jet Set and Upper Crust mock her "country" origins.
The very end of Rarity's song when she returns to her suite is quite somber. She promises herself she would put Twilight's birthday dress as her first priority, yet she goes back to her suite in the middle of the night after days of attending high class events, exhausted, but determined to work on the nowhere-near-finished ensemble ... and just falls asleep standing there. And you can't feel angry at her in that moment because she realizes what a mistake she made.
The Secret of My Excess
Spike's look of total confusion when he first sees his presents. A big deal is made out of Twilight's Friendless Background, but you've got to wonder if he had any other friends either.
Spike giving away the Fire Ruby. Here he is, with an exceptionally rare gemstone he had been preparing for months, saving for his special day so he would have something to enjoy besides the book Twilight was going to inevitably give him. And when he finally gets this close, Rarity spots it and does a very bad job of hiding how badly she wants it. As nice as the feeling of being generous might have been, it had to have hurt when he thought about what (not) to expect on his birthday. This is neutralized by the kiss Spike gets from Rarity, which is something he's wanted even longer than the Fire Ruby, which turns this into Tears of Joy.
Twilight's expression◊ when the Pony doctor is unable to diagnose anything about Spike's odd behavior is utterly crushing.
Near the end, when Spike and Rarity are falling after Spike returns to his normal size, Spike decides, in case they don't make it, to tell her he has a crush on her. But before he can finish his confession, Rarity, her eyes brimming with tears, simply puts a hoof to his mouth and smiles. She knew. She always knew.
Everypony always knew. But it's still touching all the same.
Also, Rarity's little speech to the monster before she realized who it was: it could ruin her clothes and steal things, but it was not getting the necklace because it was a gift from Spike. She may sometimes use his feelings to her advantage, and she may sometimes forget that she's meant to be the Element of Generosity but be damned, Rarity really gets it, when it counts.
Seeing Spike rampaging through town. Just imagine what Twilight was going through essentially seeing her little brother change (both physically and mentally) into a mindless monster that could hardly be recognized as the Spike she loves.
And to make that thought even worse, remember the other example Twilight knew about of somepony having their younger sibling become a monster: Celestia and Nightmare Moon. And then remember how that conflict was first settled. Twilight was being confronted with a situation where she may have needed to do something similar to Spike to protect the town and friends she loved.
Also near the end of the episode, when Spike looks over the bridge at the destruction he caused, he comes across his adult-sized footprint and compares it to his claws. It then cuts briefly to Spike's Quivering Eyes, showing his remorse for what he had done. Poor little guy...Rarity makes it better, though.
The distraught look on Pinkie's face after Spike demolishes Sugar Cube Corner.
Family Appreciation Day
All of Granny Smith's quirks are cute and used for comic relief, but it's sad knowing that she's mostly that crazy because she's really getting old.
On the other hand, her story about the founding of Ponyville is perhaps a positive Tear Jerker.
Pinkie finally cracking under the pressure of taking care of the Cakes' twin babies and bursting into tears. And the look on her face beforehand, too. You can practically hear her screaming "I CAN'T TAKE IT ANYMORE!"
The twins' reaction to it too. You can tell they really feel sorry for it. Which makes sense, as she's been their playmate since they were born more or less.
The twins' first words "Pinkie" "Pie" count for this all on their own.
Fluttershy's refusal to babysit the Cakes' twins due to Angel wanting to go on a picnic. She repeatedly begs them not to be mad at her, showing that she really takes people being disappointed or mad at her very hard.
Season 2 - Part 2
Hearth's Warming Eve
The leaders of the three tribes getting frozen solid, even if they brought it upon themselves, qualifies a small bit as this. They know they're about to die along with both their homeland and the new land they came to claim, and it's all their fault. Their second-in-commands, who just wanted peace and were willing to get along perfectly with each other, nearly receiving the same fate? Definitely this.
After the leaders are frozen, the advisers acknowledge that they could be friends as they are being frozen themselves, lean their heads together to be close to a friend as they accept what they probably are thinking are their last moments.
The Last Roundup
Everyone's heartbroken expressions when they think Applejack's not coming back to Ponyville. Made even worse when you remember the beginning of Applejack's Cutie Mark story from "The Cutie Mark Chronicles".
Granny Smith: "Our little bushel just lost one apple."
Granny's line is especially poignant when you consider that Applejack and Big Mac's parents are absent from the farm, and that she's the only grandparent still alive. This isn't the first time that the bushel's lost an apple.
The entire conversation once the town gets Applejack's letter.
Apple Bloom: Applejack's... not coming back?
Rainbow Dash: What do you mean, Applejack's not coming back? She loves Ponyville.
Fluttershy: "Applejack, we can always find a way to fix the hole in the roof. If you never came back, we could never find a way to fix the hole in our hearts."
The mailstallion who seemed so excited at the idea of everypony gathering for a surprise party for his birthday, only to have Twilight grab the letter and unceremoniously slam the door in his face without a word. Pinkie made it better though.
The dejected, defeated looks on the rest of the Mane 6's faces after nopony at the rodeo knew where Applejack was.
Applejack finally explaining why she didn't immediately return to Ponyville. She was so ashamed of not winning the rodeo and earning enough to fix town hall that she considered herself a complete failure who couldn't return until she made enough money to keep her promise. Judging from the sheer heartbreak in her voice when she said "Fine; now you know", it's clear not succeeding as she promised just devastated her.
The Super Speedy Cider Squeezy 6000
Applejack's growing anxiety over losing the farm, culminating in the Apple family losing, and somberly heading off to pack their bags. The entire town tears up and begins to have second thoughts at that last part.
Applejack: "Go ahead, everypony. Go on, y'all. It's okay."
Heck, the whole Apple family in general when they're worried about the Flim Flam brothers. Apple Bloom's watery eyes in particular are especially heartwrenching to see. Even worse is when the brothers are declared the winners, Apple Bloom gives out a little "What-?" while staring up at her sister with big eyes.
When Rainbow Dash is just waking up, you can see how worried her friends are about how she's feeling.
You can't help but pity Dash. She's the type of pony who loves to stay active. But being in a hospital prevents her from doing so. She doesn't know what to do with herself. She tries eating, telling jokes to her roommate (who can't even talk to her because of their bandages), and playing with the lights. This only lasts one minute!
When Rainbow Dash leaves the hospital. She finally finds something to do that she likes and then the doctor just pushes her out the door, leaving the only thing that gave her some pleasure behind.
Also, how far she'll go to get the book back. Seeing her enjoy so much, and then watch her steal it, really shows how much it meant to her.
Rainbow Dash, genuinely scared that if her friends find out that she likes to read, they'll make fun of her.
The face that Rainbow Dash makes when she's acting sick to get back in the hospital to read that book was crushing. Especially the little whimper she makes when Caramel chides her.
Caramel: I think I know what the problem is... A severe case of Lazy-itis!
Hearts and Hooves Day
When the camera pans around the classroom at the beginning of the episode, there is a purple-maned unicorn filly who's hiding a Valentine behind her back. She moves as if she's going to give it to Twist or the roly-poly grey colt, but she finds the colt already hugging Twist because she gave him a card. She immediately drops her card and miserably puts her head on her desk. It's easy to miss, but it's heartwrenching once it's noticed.
Cheerilee's reaction when one of the CMC innocently asks why she doesn't have a "Special Somepony" in her life is a brief but extremely depressant scowl, which she quickly wipes off before they can see it. There's obviously a reason she's single, but she'd rather not get into it, and certainly not with young kids who don't have the full concept of adult relationships down yet. Anyone who's been in her situation for a long time, especially into adulthood, knows what she's feeling and can imagine the constant questioning she's gotten over and over again from curious gossipers and would-be matchmakers who keep reminding her of it. The way she quickly reverts to her friendly-teacher voice and assures the CMC she's happy just the way she is has "practiced response" written all over it. Even worse, it all takes place on her universe's analogue to Valentine's Day.
The CMC crashed a funeral, specifically to reject the Eulogist as a suitable boyfriend for Cheerilee. This might be one of the darkest Black Comedy Bursts in the show. Not only is it a slap in the face to him, but the deceased and his/her family as well. To top it off, said Eulogist looks a lot like HansMoleman from The Simpsons.
A Friend In Deed
The scene where Cranky throws Pinkie Pie out of his house after she accidentally ruins his scrap book, and tells her that he "never, ever, ever, ever, ever" wants to be friends with her. Pinkie's response is both silly and sad at the same time.
Pinkie Pie: That's four "ever"s. That's, like... (tears up) forever...
Cranky weeping over his ruined book, which has already been heavily implied to hold mementos of his lost love.
Poor Apple Bloom not getting to play with the other fillies in Pinkie's song — and reversed when Pinkie gets her to be part of the group.
Cranky and Matilda could have happily spent their whole lives together, but because of a stupid mix-up they only meet again in their twilight years. They can enjoy them but they lost a lot of time.
Putting Your Hoof Down
Seeing sweet Fluttershy become a jerk every time she tries to be overly assertive.
Especially after she turns on Rarity and Pinkie Pie suddenly and without warning — even though Pinkie was doing nothing more than giving her free punch and laughing as she always does.
The teary eyed faces of Rarity and Pinkie Pie as Fluttershy berates them on being a fashion designer and liking parties, respectively. She's insulting what each deems their purpose in life. No wonder they ran away crying.
Plus her vicious insult of Pinkie's intelligence, done for no other reason than Pinkie being concerned about how Fluttershy was acting, and calling Rarity 'petty' when she was just defending Pinkie. This all comes from someone they consider a dear friend. Rarity's reaction to this first insult is to turn away and weep silently into her hoof.
New!Fluttershy: "I can't believe that the two most frivolous ponies in Ponyville are trying to tell New!Fluttershy how to live her life when they are throwing their own lives away on pointless pursuits that nopony else gives a flying feather about!"
You can see them tearing up as Fluttershy rips them apart, and it hurts to even watch.
The facial expressions make the entire scene hard to watch. Not only are Pinkie's and Rarity's sad expressions heartbreaking, but everything from their stunned expressions when Fluttershy first insults them to the cruel smile Fluttershy has on while she does it is perfect. Kudos to the artists and animators on this one.
It might be somewhat better or far, far worse when (ignoring phrasing) everything she said was true... At least from the standpoint of parties and clothing being things a pony could live their entire life without.
Fluttershy realizing what she's become after said speech is pretty depressing too. There's even a sad version of her trademark Squee sound when she frowned.
Spike's crying because he has no idea about his origins. He sounds heartbroken when he pleads to Twilight to tell him anything she knows about who really is and wondering if dragons can cry, even while he's doing it.
The extended sequence of the teenage dragons bullying Spike. It's portrayed in a disturbingly realistic fashion and they pick up on the thing that Spike is most insecure about at the time.
It was very upsetting to see Rainbow Dash tease poor Spike about being a "lame dragon". Heck, if it wasn't for her teasing him, he wouldn't have felt so out of place.
When Spike says he wouldn't mind living with the other dragons forever, just the look and reaction on the ponies' faces, are pretty tearjerking. Especially since they are blaming each other for him wanting to stay, and looking like they're about to cry while doing it.
This whole episode can count as one. Spike breaks down into tears twice from not having any idea who he really is.
The scenes are particularly familiar to anyone who also doesn't know his or her biological family.
Spike's refusal to smash the phoenix egg, even at the risk of his own safety. "It's just an innocent, defenseless egg... like I was!" This isn't just a moral stand he's taking here (although it's that too); he's actively identifying with the baby phoenix.
Spike photoshopping◊ himself into the photo of Twilight's birthday party in Canterlot, to which he apparently wasn't invited. What makes it worse is that picture will underscore the fact that he wasn't there every time he realizes he has no memories of it. It's just a picture that he added himself to.
Poor Fluttershy is shown crying under a tree, and Angel is brushing her mane. Fortunately her animal friends are shown helping her. What led to it is Rainbow Dash asking if she's really going to let her traumatic past push her away from the job. Fluttershy turns around, reveals that she's full-on weeping, and screams "YES!" in the most believable and saddening way possible. It's the first time in the series that Fluttershy's shyness is played seriously.
Prior to that, we have to watch her suffer through a fairly realistically-depicted panic attack.
Rainbow Dash was really looking forward to beating Fillydelphia's record. You can't help but feel disappointed that she had to abandon that goal.
The flashback to Fluttershy at flight camp. Seeing all of those foals laughing at Fluttershy makes you want to hug the poor thing.
After training her flank off to increase her wing power, Fluttershy does what appears to be a perfect run...only to end up at only 2.3. She's devastated to find out that all her training didn't get her to even half that of the other Pegasi. Rainbow Dash's reaction to it also counts, as she's at a loss of as to how to help her friend. The Element of Loyalty can't help her best friend.
If you think about it, it's sad for both Pegasi — Fluttershy asks Rainbow Dash how she'd feel if her flying skills were so weak, and Rainbow Dash doesn't have an answer. Considering just howimportant winning is for Rainbow Dash, that very idea is the worst thing Rainbow Dash could think of happening to her. Her natural talent and obsession with being the best means she has no idea what Fluttershy is going through, and it's always upsetting when you can't fully identify with a friend, no matter how much you may want to.
The entire sequence of the first hurricane failing is a notable example and especially for Rainbow Dash. RD is, all of a sudden, leading a doomed effort right in front of her lifelong hero. When the whole thing falls apart... She has crashed and failed. Again.
Rainbow Dash's expression when she realizes that her constant inability to keep from sounding condescending to Fluttershy caused her to run away crying; you could tell by the way she kicked her hind legs and snorted angrily that she was upset at herself for not taking Fluttershy's feelings into account when she verbally berated her for quitting, sad that her brusque nature made her best friend cry, and possibly realizing that she just can't relate to ponies who don't athletically measure up to her, no matter how hard they may try.
The CMC all throughout the entire second half of the episode. They know full well what they are doing is wrong, but go through with it only because Diamond Tiara is urging them to. When they finally decide they've had enough, Diamond Tiara forces them to stay through Blackmail.
The conflict in this episode is presented in a heavier, darker fashion than is typical of this show. The fact that they can't get anyone to talk to them (some won't even look at them) makes the viewer realize what a heavy cross they had to bear for their insensitivity.
What makes it even worse is that while it was indeed a heavy cross for them to bear, nopony even gives them a chance to explain themselves, even if they weren't gonna do it in the first place. Just put yourself in the CM Cs position and realize how unacceptable this reaction must be for you.
The entire town shunning the CMC after learning that they were Gabby Gums. Of particular note, Applejack is unwilling to speak to them and the normally quiet Big Macintosh voices their utter disappointment in them.
Big Mac: You should be ashamed of yourself, humiliatin' your sister 'n' me like that. We don't wanna talk to any y'all right now, so take your little gossip column and your embarrassing photographs and just GO AWAY!
The second most painful one to watch would be Rainbow Dash's reaction to the three. She pulls a cloud over their heads and makes it rain on them in anger. No wonder Spike was worried about impersonating her.
And remember, Scootaloo idolizes Rainbow Dash so having her own idol not even want to look at her must be horrible for Scootaloo
Thirdly, after the CMC find out that Twilight managed to put up a force field around the entire library, when Spike sees the fillies, the bitterness in his voice when he says that Twilight put it up in case they'd show up really makes him sound like he wants them to just rot in Hell.
Watching the CMC try to get Rainbow Dash to read their open letter apology. They endured a lot of rain stomped out by an angry Rainbow Dash before she finally sees the paper.
The sequence where the CMC visits Fluttershy after they wrote the fake article about her. It made her cry so much that her tears have flooded the floor and are leaking under her door and trailing outside.
A Fridge Horror example here. The CMC decide to stay in their clubhouse until they can make things right... and are never shown sharing this plan with anyone else. Now, Applejack and Big Mac probably knew where they were, given the location of the clubhouse, but what about Scootaloo and Sweetie Belle's families? Especially Sweetie's. Imagine it: your young daughter is currently shunned by most of the town and she hasn't come home at night. It goes further. Sweetie's parents' next logical step would be to contact Rarity and see if Sweetie was with her... and the last time Rarity saw her sister, they were fighting. Imagine how that would feel.
A Canterlot Wedding, Part 1
Who else wanted to hug Twilight when she started talking about her brother?
It really hits home for anyone who has moved away from their loved ones (or had loved ones move away from them). It's part of life, but you still know what Twilight's singing about.
Girls with older brothers who they idolized as a kid and had to watch them go far away to university will know exactly how Twilight feels at the end of "B.B.B.F.F".
Who really wanted to hug Twilight after nopony believed her accusations about Cadance? Not her friends, not her mentor, and not even her brother stopped to listen to her side or offer a listening ear, instead giving her a verbal smackdown and cold looks. It's made all the worse about 2 minutes later, when it's revealed that Twilight was absolutely right to be suspicious of the faux princess.
Shining Armor telling Twilight to forget about being best mare and not to even bother attending his wedding at all was pretty bad.
Princess Celestia's stern, ice-cold "You have a lot to think about" must have been like a dagger to the heart of poor Twilight. Just look at her face after Celestia says it; she might as well have said "I hate you. We all hate you."
The little bit where Twilight sings about losing her brother and the tiny differently animated Twilight looks around frantically for the tiny Shining Armor.
And then gets stepped on and shattered by Cadance, which foreshadows the fact that Twilight was correct.
A Canterlot Wedding, Part 2
The way everypony looked so bitter when Twilight initially crashes the wedding. They really took her outburst hard. Even Spike looks ashamed. Of course, this is seconds before she is dramatically vindicated.
Their Jerkass Realization following this, with even Queen Chrysalis pointing this folly out to them in her gloating. Despite all the chaos ensuing, Applejack even feels the need to apologize to Twilight on behalf of everypony.
Cadance tiredly performing the sunshine-ladybugs dance and the broken smile she gives Twilight. She really looks like she's been through a rough time and now she's in mortal danger at the hooves of the mare she used to foalsit! She desperately hopes Twilight will believe/recognize her.
"For I oh so love the groom! All my thoughts, he does consume. Oh, Shining Armor, I'll be there very soon!"
Blink and you'll miss it, but while Cadance desperately pushes the minecart to try and make it move, there's a tiny second where she collapses from all the stress and just cries against the cart. Twilight picks up the slack quickly, but it's still sad, and would be a lot more gut-wrenching if she wasn't singing optimistically the entire time.
The very end of the song, when Cadance briefly loses all hope of saving Shining Armor. Her eyes well up and she crumples to the ground. Making it even worse is that Cadance isn't worried about herself not getting to the wedding...she's worried for Shining Armor and how he'll be enslaved by imposter Cadance...
The thought of the poor girl imprisoned underground for who knows how long, knowing a monster was walking around disguised as her, sucking the life out of her beloved and there was nothing she could do about it.
Poor Celestia couldn't stop Queen Chrysalis. Even worse if you consider it karma for Celestia for not believing Twilight about the fake Cadance.
After the Mane Six fail to retrieve the Elements, Twilight frees Cadance and tells her to go to Shining Armor. What follows is a short, wordless sequence where Cadance, with a small hopeful smile, approaches Shining Armor...who stares back blankly with Mind-Control Eyes, not reacting to her presence at all. Cadance's smile turns into despair, her eyes well up, and she gently strokes her lover's face with her hoof before collapsing against him, holding him tight while softly crying. Give the producers credit, that sequence—about ten-seconds long—is absolutely heart-rending, and without any dialogue at all.
Connected to this — do you suppose the others, including Shining, who had been brainwashed at the time, ever forgave themselves?
The Crystal Empire, Part 1
Celestia and Luna overthrew King Sombra for his treatment of the Crystal Ponies...and he made the Crystal Empire vanish as he was being banished. Judging by Celestia's reaction to being told it had returned, she clearly didn't expect it would return someday. Imagine what it must've felt like to have the thing you just fought a villain to save disappear right in front of you.
And if you dig in deeper, it's likely Celestia still has a lot of guilt and hang-ups about this. She could very well regard losing the Crystal Empire as one of her biggest failures, second to banishing Luna.
Cadance looking so uncharacteristically weak and sad is quite depressing. Shining Armor too, with all his worry for her.
The Crystal Ponies. They are absolutely miserable, with Dull Eyes of Unhappiness to show. They remember nothing of their lives before King Sombra came to power, and they're horrified by the very thought of him.
The Crystal Empire, Part 2
Seeing Twilight's and Spike's worst fears.
Twilight's is failing the test and Celestia disowning her as a student. This isn't the first time we've seen Twilight crying. It is, however, the first time we've heard her crying. She was having an existential crisis when Spike snapped her out of it.
We don't get to see what Spike saw, but he says it involved Twilight dismissing him because she no longer needed him. He started crying and didn't stop even after he'd looked away from the door. It's worse once Fridge Horror sets in. Spike, although it can be easy to forget, is a small child. He knows nothing of his origin or his species, (sans for a brief confrontation with some cruel teenage dragons who may or may not be representative for dragons as a whole). Living with Twilight is everything he's got, and all he knows. From his perspective, there would be absolutely nowhere he could turn if he was sent away.
Rarity laments the loss of the effect that the Crystal Heart had on their appearances, to which Applejack replies that "Good things are better when they're a Rarity." Rarity chuckles appreciatively, while Spike crosses his arms and looks from side to side.
Too Many Pinkie Pies
While most of this episode is hilarious, seeing Pinkie Pie worry then finally breaking down is so depressing.
The fact that she is driven to so much distress that she questions if is the real Pinkie Pie is especially tear-jerking. It gets even worse when she stops caring about proving herself; almost missing the test because she won't move from one spot where she is digging at the ground with her hoof.
At one point, Spike says he misses the real Pinkie Pie, who was next to him and Twilight. Still not sure if she's the real Pinkie Pie, she quietly says she's sure the real Pinkie Pie misses her friends too.
Pinkie Pie crying and the way way her voice sounds genuinely on the verge of tears. Just look at this◊ without tearing up a bit.
One Bad Apple
Sweetie Belle: "Then, why do I feel like...crying...?"
Then she finally does when Babs takes away the CMC clubhouse. Why Babs, Why?
We've seen the CMC sad before, we've seen them somewhat hurt by Diamond and Silver's bullying, but this is WORSE. It's clear Babs' bullying cuts deep and the poor fillies are genuinely hurt by it. To cap it all off, Sweetie Belle finally breaks down crying...poor fillies.
The premise of this episode could be one, for anyone who has been teased and bullied.
What makes it worse is that, it's a family member that's bullying them. Rather than stick up for her own cousin, she becomes her tormentor.
"We never did anything to you!"
The worst part? They were so excited about making friends with her. And then she turns into a WORSE bully than the ones they've already dealt with.
This verse of the song sums it all up:
Can't you be nice? Can't we be friends? Isn't it sad, is this how it all ends?
Though the rest of the song is upbeat, this part is pretty somber. Again, the CMC showed nothing but kindness to her, and she makes their lives miserable. Even in the midst of her bullying, the CMC hold no ill will against her (Not initially) and wonder "why can't we be friends?"
One could feel sorry for Babs after learning that she was bullied herself. If what she did to the CMC was bad, imagine how much worse she was treated by herself in Manehattan.
The bullying was so violent that she turned to Sweet Apple Acres for sanctuary. Let that sink in for a minute.
There's the part near the beginning where the CMC mention she's a blank flank, and how uncomfortable she looks. It was great foreshadowing for the later reveal, but also shows just how sensitive bullying can make someone..
After finding out Babs's was bullied back home, some of her lines seem to have more meaning once she arrives in Ponyville.
Scootaloo: This is gonna be the best week of your life!
The bullying was so bad, she hides her flank with her tail subconsciously. Even when surrounded with family and friends who don't care about it, or think it makes her even more special then if she weren't a blank flank, her tail still covers her flank whenever somepony mentions cutie marks.
Also, the CMC being too hard on themselves by calling themselves bulles after finding out what they did.
Apple Bloom saying that Babs had thrown her out of her own bed! Where does she sleep then? On Hay! The poor filly...
Twilight didn't have time to say a proper goodbye; Trixie literally threw her out of town and, to ensure no one would go after her or that she wouldn't come back, sealed Ponyville off in a giant bowl. To see Twilight's hoof pressed against Spike's claw, separated by the barrier...
Imagine what Spike would be going through. Twilight hatched him; she's like his mother!
While it by no means justifies anything she does in the episode, it is rather sad to see Trixie's life was ruined by the Ursa Minor incident. Jerk or not, she did not deserve having her caravan vandalized.
Trixie's rule of Ponyville, which gets worse and worse as Alicorn Amulet further corrupts her. Amongst the things she does is force the mouthless Pinkie to dance against her will and trap the Mayor in a cage.
Rarity is forced to design tacky clothing for Trixie. While sewing something she accidentally pricks her hoof with the needle, and makes a very saddened face.
Pinkie Pie driven to tears from being unable to eat.
Sleepless in Ponyville
Scootaloo tearing up as she finally confesses to Rainbow Dash that's she a scaredy pony who's afraid of her ghost stories but didn't want to admit it because she was especially afraid of losing Dash's approval. In fact, as Luna points out, losing Dash's approval scared Scootaloo more than any of her nightmares.
Especially heartbreaking is the escalating desperation in Scootaloo's voice as she explains how she wanted Rainbow Dash to fill a big sister role for her.
It was rather hard to watch Scootaloo struggling with her fears for the most part by herself in this episode. It was always known how much Scootaloo idolized Rainbow Dash and that, unlike Sweetie Belle and Apple Bloom, she didn't have a Mane 6 character as a sibling. But to see the contrast of Applejack and Rarity acting the part of a legitimate Cool Big Sis to their younger siblings while Scootaloo fretted about her nightmares and impressing Rainbow Dash without that same comforting figure was sad to see.
What maybe was even worse was the sheer look of panic on Scootaloo's face when Rainbow Dash doesn't initially appear when Apple Bloom, Applejack, Sweetie Belle, and Rarity do. The whole camping trip was her big plan to get closer to Dash, and for a moment it looked like it was going to utterly fail. How depressing would the camping trip have been had Dash decided not to come along...
Scootaloo resorting to humming all night in an attempt to comfort herself after her first nightmare. You have to feel sorry for the poor little filly.
Rainbow Dash's reaction after saving Scootaloo from the waterfall. Her expression and tone make it easy to see she was worried sick about Scootaloo.
Scootaloo's reaction after her first nightmare and her running into the woods to retrieve some twigs. How she screamed, it's absolutely heart-wrenching. Scootaloo is known that she "normally" brushes over fear, but here, she was utterly terrified!
The moment after Rainbow Dash tells Spitfire off and says that if being reckless would get her into the Wonderbolts she didn't want it anymore. The door closes behind her and she sags as the realization of what she just did hits: She just walked out on her lifelong dream.
It's not just that, either. Not only her dream gone, but there's a serious element of Broken Pedestal involved. Rainbow Dash has looked up to and idolized the Wonderbolts for her entire life, and for that moment she's lost all respect for them because she believes that they don't value the safety of other ponies. She's been spending her life pursuing something only to realize that she can't respect what it stands for. Which makes it all the more heartwarming when Spitfire catches up to her and explains that she was completely right.
Spitfire didn't know what was going on. She didn't even know about the tornado until Rainbow Dash storms into her office and informs her that she no longer respects the Wonderbolts. It's obvious Spitfire respects and enjoys working with Rainbow Dash and fully expects her to earn a place in the Wonderbolts when she's grown up a bit. From her prespective, the most promising of all the cadets just quit because she thinks the Wonderbolts don't care about anypony's safety. If Spitfire hadn't been furious at the reveal of just how reckless Lightning was, it wouldn't just be a moral disagreement that made Rainbow leave; in that moment, Rainbow Dash genuinely thinks that her heroes wouldn't care if her friends had died. That's a deal-breaker for good.
While it's mostly played for laughs, Pinkie Pie seriously believed that Rainbow Dash would forget her and all of her other friends the longer they stay out of contact, even if it's only been a few days. How fragile is Pinkie's confidence in keeping friends??
Rainbow Dash clipping her wing during the flag exercise. Just from the expression on her face you can tell that she was really in pain.
Also her nervousness about attempting the move at all makes perfect sense, given how many times she's badly injured her wing in the past trying moves that she knew weren't safe. It's made only worse since Spitfire, Dashie's favorite hero, doesn't care about Dash's well being and rewards Lightning Dust for breaking the academy record.
After all of Apple Bloom's excitement at the chance to hang out with Babs again, seeing that give way to exhaustion and her repeatedly thwarted attempts to just make small talk is pretty sad. Especially in light of how when they first met where most of the week was wasted by poor communication. Here they have a second chance to spend time together, and again it's torpedoed — and this time, it's because AJ, the same pony who told them they could've avoided all the heartache last time, isn't listening!
Applejack getting teary-eyed after accidentally destroying the barn.
Applejack: Oh Granny Smith, here you let me be in charge of creatin' great memories, and the only thing anypony's gonna remember about this reunion...is that it was the worst one we ever had.
Might be more of an example of a Fridge Tearjerker during this episode, every member of the Apple family came to the reunion, and Applejack's parents were nowhere to be seen. At the end of the episode, you see two shooting stars side by side. Since Lauren Faust considers Applejack's parents to be dead...
Another idea by Faust was that they were traveling sales-ponies, and traveled all around the world. Which means that they'd be too busy to see their own kids, and other family members. While this alternate backstory wasn't used, it's still pretty tearjerking (for anyone who wants to read more about it, it appears in this FAQ).
The shooting stars also appeared near the beginning when Granny Smith was talking about how "Not everyone would be able to make it" the next time. Then Applejack looks up at the sky and sees the two shooting stars which later appear at the end.... it seems that it's confirmation that Applejack's parents are indeed dead.
Confirmed by Sibsy on her Twitter.
Spike at Your Service
Throughout the episode you see Spike do work for Applejack to repay her for saving him from the timberwolves, by following the noble dragon code, which is very sweet of him to do. Then you realize that there's more to the code than helping Applejack. This scene gives us a good example of what it is:
Spike: (talking to Applejack) Maybe you need help remembering your favorite song. A dragon is the finest creature ever! There's more to them than just guarding treasure.
It then makes you realize that he's doing all this to show everyone that dragons aren't just beasts. He's willing to follow this code just to prove his point.
When Applejack keeps trying to tell him that she doesn't need his help, the poor little guy looks so upset whenever she tries to do this. It shows his desperation to show her that he's noble.
When Spike tells Twilight that he's going to serve Applejack forever you can tell he's broken up about telling her this. When he does and she says yes (only because she wasn't paying attention, and was reading a book) you see tears in his eyes, as he leaves.
It's subtle but after she finally realizes what happens from Applejack (met with a horrified Big "WHAT?!") and admits she wasn't really paying attention to him, she looks noticeably ashamed of herself. This is probably one of the most evident cases of Twilight realizing how much she takes Spike for granted.
This is made all the worse after you remember what Spike's greatest fear was in "The Crystal Empire". When Spike tells her that he's leaving for Applejack's, the way he says it sounds like he's hoping Twilight will say no or talk him into staying. Because she's so distracted from reading, the way she says yes makes it seems like she doesn't care that he's leaving and would be fine with it. His one real parental figure is unintentionally saying that she doesn't want him with her anymore... meaning that said fear technically came to pass. This puts his desperation to serve Applejack into a much harsher light.
Not only the Heel Realization moment, but the one preceding it in Fluttershy's cottage. Listen to Discord's voice after Fluttershy calls him her friend, the utter disbelief at that single statement. Look into his eyes and hear his voice crack a bit when John de Lancie reads the line that follows. You can tell from that how sincere he is, that this is truly the first time someone's ever considered him their friend. Poor guy...
Discord: Oh... Well, I've... Never really had a friend before...
Seeing Discord tear up is something, to say the least.
More of a Fridge Horror type of tear jerker than anything else, but, Discord saying that he's never had a friend before. Imagine being thousands of years old, having no understanding of friendship, and due to your actions in the past, everyone sees you as an evil monster. Intense loneliness (and the Nightmare Force) is the same thing that turned Luna into Nightmare Moon.
Nobody in the world except Fluttershy ever thought there was any good in him. When nobody reaches out to you, how can you yourself know whether you're capable of redemption. In the end, when he sacrifices his World of Chaos in exchange for keeping Fluttershy's friendship, you can tell that despite his reluctance to go soft there's an It's All Junk revelation in his voice when he admits that being friends is more important to him.
A Fridge Horror tearjerker: Discord is immortal. Fluttershy is not.
Just For Sidekicks
When Spike mentions to Fluttershy that he wasn't invited by Princess Cadance to join Twilight and the others in welcoming the important Equestria Games inspector (for the next episode), you really feel bad for the little guy. You can clearly tell that he feels left out. He helped save the Crystal Empire and the fact that he wasn't invited to participate in doing anything with the Princess of the Crystal Empire is insulting.
In the beginning, we find out that Peewee was given back to his parents.
Poor Spike never did finish that cake.
While Spike lost most of his gems to pay for the trouble his plan to get the gems caused, Zecora promised aide and then gave the gem away. She had good intentions but the look on Spike's face is awful.
The increasing revelation of Spike being a No Respect Guy (and to some extent required to). He lost his own housepet offscreen, and can't have even a small number of cherished possessions without his greedy instincts kicking in (as karmic as it was, you have to feel his frustration at having part of his earnings taken from him to prevent this). His best redeemer is being "rich" in love and respect, and as shown in this episode, he sometimes gets short changed ins that as well. The poor guy Literallycan't have nice things.
One can't help but feel a bit sorry for Angel when Spike keeps him from getting to Fluttershy and drags him back to the train. Angel was squeaking and apparently crying all the way. He most likely really missed her and wanted to see her again, not just to get Spike in trouble.
Game Ponies Play
Rainbow Dash's memory of Cloudsdale not being picked. She looked so excited then when she learned Cloudsdale wasn't she was clearly heartbroken. She was just a filly at the time...
Magical Mystery Cure
Seeing Sweet Apple Acres and Carousal Boutique in boarded up and diminished conditions is unsettling considering they're normally very busy and populated places. It's very nostalgic. Twilight is lamenting (in what could be considered the saddest song in the entire series) how everypony is struggling with their new destinies and have given up hope, which causes Ponyville to rot away while the Mane 6 look on helplessly. The whole sequence could be considered one of the saddest moments in My Little Pony history, previous generations included.
Moreover, watching Applejack board up Carousel Boutique is very unnerving.
At the start of the song, Spike looks at Twilight as she goes up the stairs with a very sad expression. The spikes on his head even droop.
The position that the Mane 6 sans Twilight is in sucks. Imagine something that you're horrible at. Now imagine being suddenly compelled to do it as a living. Furthermore, you and everyone else knows this is what you're destined to do, for the rest of your lives. Oh yeah, and because you're horrible at your job, you can never really be happy doing it. They apparently forget that they ever had their previous lives, thus thinking they were born to do something they're bad at. Ouch.
Fluttershy, the pony with crippling anxiety and fear in crowds has something that compels her to be the center of attention. She felt that it's better to move back to Cloudsdale than stay. Note that Cloudsdale is a place where she was never accepted (and apparently bullied a lot) and doesn't work well with her fear of heights.
When the gang comes to help them, Applejack and Rarity are both in tears, as no matter how hard they try, everything they do falls apart around them. How many other times have they all been reduced to tears with how horrible their lives were?
Applejack takes great pride in hard work and perseverance. Having her fail at something she hates but compelled to do adds another layer to this onion of a problem. This is Applejack. Tough, dependable, stable supportive Applejack. Even when she was at her lowest in other episodes, she never cried. Seeing Applejack of all ponies on the edge of a breakdown was heart-wrenching.
The previously joyous Pinkie Pie is increasingly frustrated and declares that her life sucks. Despite working as hard as she can, the farm is dying around her. Especially heartbreaking is that she was miserable during her childhood on the rock farm, and now believes she's doomed to live through that childhood for the rest of her life.
Oh yeah, and her mane is flat again. Just seeing Pinkie with her sad flat-hair look again is depressing.
Heck, Pinkie Pie, happiness personified, uttering the words "it's no fun being me" is heartbreaking. If this were anypony else it wouldn't be so bad, but this is PINKIE PIE!
Note that Pinkie doesn't smile even once until her cutie mark returns.
Rarity's inability to manipulate the weather properly is angering the other ponies in town. It's hard watching her flinch under everyone's glares. Some ponies literally slam doors at her. Her lowering her head in despair during her own rainstorm after that display is horrible to behold.
Watch when Rainbow clears the cloud above her: Not only is Rarity in tears, but she actually flinches, recoils, and starts trembling like she thinks her own friends are going to hit her until the rain stops above her head. Just what have the citizens been doing to her for her poor handling of the weather? There's also the fact that in Twilight's song, she doesn't care that her mane is wet, something she often freaks out about even in a light sprinkle.
Rainbow Dash has had such a bad time with the animals that she simply stops trying. The most brash, most loud, and most fearless pony of the Mane 6 is reduced to a depressed heap on the cottage floor. Now THAT'S sad.
Even worse: she doesn't even try to escape when the animals tie her up and put her into a pot.
Twilight isn't spared either, since it was her spell that caused all the unhappiness. Her "What have I done?" moment at the end of her lament song is absolutely heartbreaking. In fact, she might be the most miserable of them all because she knows what's truly going on. Just imagine watching your friend's lives go to hell, them being miserable beyond all reason...and there's no one to blame but you.
Everyone's reaction when Twilight reverses the magic. Their Cutie Marks are restored but the magic immediately re-surges back onto Twilight and she disappears, leaving an enormous scorch mark on the ground resembling her Cutie Mark. To the lay observer, it looks like the magic OBLITERATED their close friend from existence. Many have noted the potential Tear Jerker Alternate Ending ◊.
Additional Tear Jerker given Twilight's expression before she disappears. She's alarmed by the Elements firing and encircling her in magic but then she simply smiles and bows her head, as if accepting whatever will happen (even if it means death) as long as she knows she undid her mistake and restored the life purpose's of her dearest friends.
Twilight and her friends are both sad that they can't spend the Summer Sun Celebration together, Twilight even mentioning that it's what brought them together.
Celestia reveals that for a thousand years, the Summer Sun Celebration was a reminder that she'd had to banish her own sister, and that she's glad that it isn't like that anymore.
She also acknowledges that it was a time of celebration for everyone else, and so was putting on a brave face for her subjects while secretly hurting inside.
Celestia and Twilight nuzzling, after she promises to always be there for Twilight and hopes that Twilight will do the same for her.
The revelation that the Everfree Forest had become so overgrown that Zecora had to flee from it. Recall that Everfree is her home.
Princess Twilight Sparkle, Part 2
Twilight witnessing Luna's corruption and Nightmare Moon's origin via Flashback, and how Celestia was forced to banish her own sister.
In particular, Twilight sobbing over the body of a (temporarily) defeated Princess Celestia, before she realizes it's not real.
It's even worse in hindsight: Up until Celestia summoned the Elements of Harmony, Twilight had no idea she was a thousand years in the past. She thought that Luna had become Nightmare Moon a second time. For all Twilight knew, Celestia was dead.
It's made even worse by the fact how Celestia screamed when she was defeated by Nightmare Moon. That scream wasn't the scream of someone wounded, it was the scream of someone in their death throes!!
Luna's corruption was already horrible, but look at the elements she used against Discord. One of which is Loyalty, and another being Laughter.
Take a close look at Celestia when she banishes Nightmare Moon. She's◊ crying.◊
Celestia's voice actor does a spectacular job of delivering her lines, especially as she begs Luna to lower the moon and insists she will not fight her sister. It only adds to the emotional impact of the scene and does an excellent job of portraying a normally stoic and calm character as desperate and remorseful.
Watch this whole sequence again. Then go back and watch Celestia and Luna's reunion at the end of episode 2 of season 1. Cry an ocean.
Twilight and her friends manage to save the day again, but have to give up the Elements.
Even worse, earlier when Twilight was worried about her new duties affecting her friendships, Applejack says that the Elements are what keeps them all connected. When Twilight tells her friends they need to give up the elements, Applejack brings this up again. It seems like she believed the Elements were the only reason someone in Twilight's position could still be friends with her. Thankfully, Twilight gives a heartwarming speech to reassure her.
Also, Twilight's friends feel she should keep out of it. Because supposedly Celestia and Luna might not even return if they succeed in their mission, Twilight will be the only princess to take the throne in Canterlot, and they don't want anything to happen to her. Though she feels they're right, she's still saddened by their decision. It pains them to have to do this too.
A bit of Fridge Tear-Jerker occurs when Discord taunts Twilight over choosing to go back to Canterlot instead of joining her friends to help save the Tree Of Harmony (Granted, he was doing so to get Twilight to help them). It may come off as him being a jerk at first, but then you realize that one of the ponies out in the Everfree Forest is Fluttershy. Not only is Discord essentially teasing Twilight over thinking her duties as a princess come before her friends, but he's also berating her for allowing said friends to get themselves into danger without her there to save them. In other words, we have Discord essentially showing concern for the other ponies (especially Fluttershy's) well-being and him calling Twilight out on her actions.
Fluttershy worrying about Angel, especially when we know he's fine.
Fluttershy sobbing over what she thinks is Angel crushed by a pillar. Even though we know from the start it's fake, it's quite startling to see the show go somewhere so dark.
Tears of laughter tend to flow at the climax, with four of the Mane Six running around in a state of utter panic while Twilight looks on in confusion.
The diary entry mentions how much Celestia and Luna loved their castle. Then you remember about the previous episode: prior to becoming Nightmare Moon, and even prior to blocking the Sun, Luna's first act after her Face-Heel Turn was to angrily tear the castle apart without giving a damn about it. After becoming Nightmare Moon, she keeps destroying it for lulz. It's somewhat subtle, but this just underlines all of Luna's bitterness towards Celestia.
On a related note, after imprisoning Nightmare Moon, Celestia chose to move to Canterlot instead of repairing the destroyed castle: the former place of happiness became just a reminder of pain and regret.
Rainbow's Heroic BSOD over her failure to help Daring Do. It really crushes her spirit. After Daring gets captured, Rainbow Dash ends up sitting still in a depressed state for several hours. It's daytime by the time her friends find her and by that point Rainbow Dash is more than ready to just go home and leave Daring Do be. It says a lot about Rainbow's insecurities when this is how she reacts to letting down somepony she respects.
Flight to the Finish
A season-wide one, which began with Sweetie Belle's cameo in the first episode and becomes more pronounced here: Michelle Creber, Claire Corlett, and Madeleine Peters sound much more mature than they did the previous year. It's a painful reminder that childhood doesn't last forever, and they just seem to sound older with every passing episode.
Getting even more meta is the fact that you can really hear the effort they're making in still trying to sound young. Claire Corlett can be heard inducing her iconic voice cracks. You feel like comforting the actresses, assuring them that they still have job security.
Diamond Tiara and Silver Spoon have perhaps their biggest Kick the Dog moment ever when they taunt Scootaloo about her inability to fly. Basically the pegasus equivalent of mocking a kid in a wheelchair.
Unidentified Brony at Comic Con: Poor Scootaloo.
Scootaloo being so upset about not being able to fly she throws away her scooter and flying posters.
Scootaloo's actions towards the end (telling her friends they're better off without her, and throwing away her most prized possessions) are nearly identical to that of someone who is suicidal.
This one line from Scootaloo can really stab you right in the heart.
Scootaloo: But Rainbow Dash... what if... what if my wings never grow? What if I never fly?
This episode retroactively adds some tragedy to Scootaloo's entire character. For three seasons, we've been taking it for granted that she can't fly because of her age - somehow forgetting that we've seen many pegasi her age flying just fine. Maybe Pound Cake isn't a prodigy, maybe he won't lose his ability to fly when he gets older. Diamond Tiara and Silver Spoon must have unearthed some very deep-seated insecurities - her inability to fly has probably been Scootaloo's Elephant in the Living Room for a long, long time.
Spike throughout the whole episode can be considered one big tearjerker.
To elaborate a bit, it is made pretty clear that the reason Spike dislikes Humdrum in the comic is not just because the character is for comic relief or is rarely helpful... it's because it reminds him of himself. That's the opinion he has of his own status on his own little 'team', meaning his self-esteem is suffering. Even sadder, things only go back to the same as before after this episode.
At the beginning when the others are cleaning the castle, they say they don't need him. The poor guy looks over to all of them working together, and walks off feeling useless.
When Spike realizes he's been turned into the powerless sidekick he's too afraid to help because he doesn't think he could be useful.
To make things worse, when Mane-iac kidnaps the Power Ponies, they could very well be killed, and Spike would be stuck in there permanently, had he not gotten over his fear and tried to save them.
When it looks like Mane-iac is about to spray Spike with the hairspray to freeze him, she tells him that he isn't even worth it.
You'll cry tears of joy with Spike when Twilight says even if they don't always need Spike's help, he always comes through for them, and they have faith that he'll save them.
The mane six, sans Fluttershy, agreeing with Applejack that the vampire fruit bats need to be stopped, proceeding to parade around Fluttershy while ominously chanting "Stop the bats, stop the bats, make them go and not come back!" while she just looks on in shock and fear. And at the end of the song, Applejack marches up to Fluttershy and practically yells in her face as she crawls backwards on the ground to get away from her. Oh, and in case you didn't read that properly, let me remind you that this is Fluttershy they're all yelling at.
And later on, they practically force her into using the Stare despite her obviously not wanting to.
There's also Fluttershy's apology right before she uses the Stare on the bats, and you can really hear the pain in her voice as she prepares to do so.
In regards to Fluttershy's transformation being her (and the others') fault:
Applejack:...I just want my friend back.
This exchange takes on a whole new meaning in light of Spike's doubts in the last episode:
Applejack(to Fluttershy): I wanna thank you for your help. I couldn't have done it without you.
Spike: Aw, don't mention it, Applejack. It was my pleasure! Really!
It's clear that he's still feels so useless that he has to take credit for something that he had absolutely no part in. That's pretty damn sad.
Applejack sacrificing her giant apple, which was going to be entered into a contest, to lure Flutterbat in so she could be returned to normal. The look on her face before she's about to cut it open (and after Rainbow Dash reminds her of what she's giving up) is obviously her holding back being upset in favour of getting her friend back to normal.
Think about what the latter part implies, too; Rarity represents the Element of Generosity. Generosity is a defining characteristic for her, a major facet of her personality. To be told that something that so defines her is completely and utterly worthless in the real world must have been awful for her.
After the fashion show, Rarity sings a Dark Reprise of "Generosity", where she laments how horrible she was to her friends and how she might've forever damaged their bond.
Made sadder by the fact that she's acting out of her usual character: only one other time has Rarity been so upset she doesn't care that her mane got ruined, and that was in "Magical Mystery Cure" where she was suddenly the most hated pony in Ponyville.
Look at Spike after Rarity says she'll be staying in Manehatten for a while. He doesn't say anything, but he looks absolutely heartbroken.
Spike throughout the whole episode. In Power Ponies, it showed that Spike is not just comic relief or the Butt Monkey of the group. Yet in this episode he's once again nothing but that.
Rarity still has some Pet the Dog moments with him, so his contributions are still noticed and appreciated.
Plus just the fact that he's there, after being left out on some of the other trips, is nice.
Coco Pommel really gets put through the wringer in this one, having to withstand some of the harshest verbal and emotional abuse the series has seen to date. Much of the time, she looks about two seconds away from collapsing into sobs. It makes the episode's denoument all the sweeter, though.
You can't help but feel bad for Soarin for most of the episode. While injuring his wing was bad enough, his teammates decided to not only not visit him, but also considered outright replacing him with Rainbow Dash.
And not just his teammates, in his own words, no pony has visited him, period. No family, friends, team staff, not even a fan dropping by for the chance of meeting one of the Wonderbolts. Poor guy...
What about Dash herself? A pony as competitive as Dash had to be seriously looking forward to the event, but upon being forced to choose a team, she thinks it'd be better to miss the event entirely by faking injury.
Pinkie thinking that nopony needs her around as a party planner anymore because they've got Cheese, especially since the episode opened with her singing about how much she loves party planning.
Pinkie: If Cheese really is the super duperiest partying-est pony of them all, maybe that means... I'm... not.
When Pinkie realizes that she's ruining Dash's special day with her competitiveness and pride, and forfeits the goof-off.
Cheese's realization that he's won the goof-off. At first, he laughs as if to say "Well, that's to be expected", but then it dawns on him: Pinkie Pie, the inspiration for him becoming the super-duper party pony that he is today, and probably looked up to her a lot, just quit. You could tell from his "...I do?" that he was expecting a challenge all the way to the end, and he would've been happy, win or lose, because he got to match skills with Pinkie Pie.
Little Cheese being shy and alone.
It's subtle, but the brief pained expression◊ on Cheese's face right before he confesses about his past implies that it still hurts him to think about it.
The way Pinkie deflates her balloons in "Pinkie's Lament". She hugs them, very gently, and the air just slowly blows out of them. For Celestia's sake, Pinkie managed to make deflating a balloon heartbreaking!
This episode seems to confirm that Spike's crush on Rarity is essentially hopeless. This wouldn't be as bad if it weren't for an earlier episode confirming he has self esteem issues. For anyone who's been in his situation in real life, it can be pretty depressing.
What may actually be a positive tearjerker though is that it isn't entirely hopeless. Unlike how Rarity was treated by Trenderhoof, Spike was never treated like he needed to change who he was for Rarity. She likes him, no matter who he is. It shows how sincere their feelings are for one another (romantic or platonic).
Except that she's always known about how he feels; even though everyone already knows about it, not much is said about his essentially hopeless chances.
Season 4 - Part 2
Fluttershy's Heroic BSOD upon realizing everyone just saw her singing. Even though the audience's reaction is nothing but positive, her fears distort it into staring blank faces cruelly mocking her and she runs away in fright.
May or may not count, but notice Big Mac's face after his flashback. He looks so sad and disappointed, possibly because he knows he's letting his friends down, but also because he was beaten in the turkey call contest after being undefeated for 6 years. Imagine how he must feel, having something he was very proud of, judging by his grin, and then suddenly having that something taken away from him.
The CMC are just so happy that all the other kids are paying attention to them, suggesting that usually they get glossed over or ignored or made fun of by them - probably because of Diamond Tiara's influence.
The CMC try really hard to prove to Twilight that they did really want to learn from her, but they almost screw it all up.
Twilight's disappointment that the other kids and the CMC aren't really there to learn and are just hanging out with her because she's a princess. She wants to be valued for what she knows, not because of her status. When she says to the other fillies "Well... neither did any of you", you can feel the sadness based on the tone of her voice.
Fridge Tear Jerker - Maybe Twilight understands what the CMC went through because she was used to having other foals try to befriend her just because she was friends with a princess.
Another Fridge Tear Jerker. Twilight has worked really hard to gain respect and acceptance in Ponyville for who she is. Her popularity due to being a Princess may have forced her a few steps back on progress.
It Ain't Easy Being Breezies
At first, it seems as though Seabreeze is a Jerkass who can't lighten up, but once he's gone out into Ponyville on his own and is nearly killed by a falling acorn and has to face an angry swarm of bees, it's hard not to feel bad for him. And then, you find out why he's really so anxious to get home — he's got a wife and child waiting for him.
That makes the moment he burst into tears in Fluttershy's home a tearjerker in hindsight.
Spike's guilt over causing the Breezies to be left behind.
Fluttershy bursting into tears after she orders the Breezies to leave her house.
Somepony To Watch Over Me
Given that Word of God has already confirmed Applejack's parents are indeed dead, her overprotectiveness of Apple Bloom can take on a rather dark edge.
Pinkie's mane deflating when the others respectfully decline making rock candy necklaces for Maud.
Applejack: It just wouldn't be right for us to make something that shows we're friends if...well...we aren't.
It's worse than that; Pinkie Pie physically strains herself to keep from crying, then puts on a sad little smile and says, in an absolutely heartbreaking tone of voice, "Oh... okay. If anypony needs me, I'll be in here trying to figure out what to do with two hundred pounds of rock candy...". The looks on her friends faces adds to the scene; you can tell that they feel absolutely terrible about having to put Pinkie through that.
The whole situation is sort of a hard pill to swallow for Pinkie. Finding out that her best friends and her sister are so different that they cannot easily get along is a bit heartbreaking for someone like Pinkie Pie whose entire character revolves around being friends with everypony and making others happy.
"But... We never even got to make our rock candy necklaces..." Pinkie sounds on the verge of tears saying it.
For Whom The Sweetie Belle Toils
Rarity's breakdown sequence in Sweetie Belle's dream was very painful to watch.
All the while Sweetie is begging Luna to end the nightmare. That was equally as painful. Seriously, Luna didn't pull any punches with that dream, but it was necessary to show Sweetie Belle that nothing good comes from petty acts of jealousy.
The worst part would have to be when Fluttershy knocks on Rarity's door asking her to make her a dress, and Rarity refuses, informing her that she no longer makes dresses. This incident was apparently so horrible it got her to stop doing what she loved. Not just as a career, but altogether, even for her closest friends.
Sweetie Belle's fifth birthday. Both for Sweetie Belle's tears in response to her friend's insensitive remarks but also for Rarity's determination to try and keep the party going even when Sweetie is a no-show.
Luna confiding with Sweetie Belle that she knows, all too well, what it feels like to be in the shadow of an older sister who always seems to outshine you. She shows Sweetie that Bad Future scenario to make sure this little filly doesn't experience the same downfall she did, letting her jealousy consume her.
Rarity's treatment by Sweetie Belle. After Rarity goes well out her way to help with the costumes at the last minute, despite working on an order for an extremely important client, it gets thrown back in her face. She may have her flaws, but Rarity clearly loves her little sister very much and has always tried to look out for her.
Leap of Faith
Applejack's dilemma. On one hoof she blows the lid on the tonic and takes away Granny Smith's happiness that came from it. Or she sits on standby and watches as Granny spends bit after bit on tonic and performs increasingly life endangering stunts. Not to mention having to "endorse" the product so other ponies to keep up the charade many of which will probably only barely benefit from what is essentially vegetable juice, causing the lies to build-up and grow while wearing on her conscience.
Once Rainbow Dash realizes that her goofing off might cost her her dream of joining the Wonderbolts, she is crushed. She starts moping about and at one point, she lands on a cloud, and the cloud suddenly darkens into a rain cloud.
Rainbow Dash: Yeah, I get it. I wouldn't want to hang out with a loser like me either...
The worst part by far is that she just gave up. She even says she's just too dumb to learn and is doomed to fail and starts pondering getting a menial labor job since she's convinced she's going to flunk her Wonderbolts test, including working on Pinkie's family's rock farm, shining shoes, and digging ditches.
Spike when Rainbow tells him no more plays, he tears up and just looks so sad. Made worse by the fact that he doesn't make any other appearances in the episode after that scene.
Rainbow's line "Too bad I'm just too dumb to learn anything" hits home for people that weren't good students in school due to a learning disability, disorder, or different method of learning than the norm. A kid who has trouble reading due to dyslexia or isn't good at math due to dyscalculia (basically dyslexia with numbers) or has trouble sitting still and listening due to ADHD may have even said those exact words about themselves.
Rainbow Dash's reaction when she finds out that she just sold Fluttershy. She feels terrible over what she has done.
The background of the lamp trader Stellar Eclipse - designed and voiced by an 18-year-old brony with spinal muscular atrophy, who got the gig via Make-A-Wish Foundation - just might make you shed a tear of bittersweet joy.
Rarity being told that her idea for the puppet theater was no good. While once again, her breakdown was played for laughs, she took it pretty badly.
The way Spike talks when he says that he will tell Rarity the truth about how she is getting carried away with the spell and how he fears that when he tells her, she won't be his friend anymore. Giving that he has a huge crush on her, you can tell that what he's about to do is painful for him.
The fact that it was his fault that his friend began to act in this manner is a bit sad and terrifying in itself.
You can't help but feel bad for the young fillies after Rarity changes their party. Some of them even look like they're about to cry. (Hopefully Pinkie and her reality warping party powers were able to save the day.)
Seeing Spike look totally dejected after Twilight tells him that she lit the torch and refusing to even come out of his room because he's so embarrassed over the anthem incident.
Twilight's library got destroyed by Tirek. Seeing a character's home get obliterated (something often threatened but never actually done) is just heart wrenching.
The look on Twilight and Owlowiscious' faces upon seeing the wreckage makes it even sadder. Think about it. All the memories they had inside the library. All the things that she found joy in and the memories associated with them. All gone. To anyone who's lost their home and their belongings to a tragedy such as this, this scene hits close to home. And unlike the frequent destruction of the Apple family's barn, which is Played for Laughs, this one is played entirely straight.
Fluttershy's reaction when she discovers that Discord betrayed them for Tirek. And Discord's expression when Tirek imprisons Fluttershy. AND Discord's reaction when Tirek betrays him.
Discord's entire demeanor from his betrayal up to the final musical number is this. When he and the others are trapped in Tirek's bubbles, he's slumped and keeps looking away from everyone. He is completely and utterly broken by what he has done. Not only has he doomed Equestria, but he thinks he's lost his friends as well.
Then when Twilight demands that Tirek release her friends in exchange for her magic, Discord remains imprisoned. Twilight says all of my friends. And when Tirek questions why she'd call Discord a friend after his Face-Heel Turn, Twilight just demands that he release him, thus turning the above moment into both this and a Crowning Moment of Heartwarming.
The whole business of Discord's treachery. Tirek's offer works because he claimed he could give Discord something that he'd lost. His betrayal works because Discord has learnt of friendship and truly believed Tirek considered him a friend. In his mind, Discord perhaps thought he was getting the best of both worlds - a friend and the freedom to cause chaos - and Tirek played him. If Discord hadn't been affected at all by his friendship with Fluttershy, he never would have trusted Tirek or given him the chance to take his magic.
There may be more. Discord was brought back out of stone because Celestia wanted his power on her side. He heard her say that. Furthermore, during his other appearances, it's really clear that aside from Fluttershy and possibly Pinkie, he doesn't have many people who actually seem to like him. Given his taunt 'Surely you must've seen this coming', it's possible that another reason Tirek could sway Discord like that was that he convinced him that he doesn't have any friends at all, that he's just being used until his masters think he's too inconvenient. That Tirek was able to do so in just one exchange of dialogue is either dramatic convenience or a sign that Discord really does think he's just a tool for the princesses to use. Then Tirek uses him.
Right after the moment above, Discord softly says he's sorry to Fluttershy, who simply answers with a sad "I know." while in tears.
Seeing DERPY get drained of her magic and rendered flightless.
Early on in part one, Discord asks Fluttershy about tea later on, she agrees and he says "I'll bring the cucumber sandwiches" yet after his heel-face turn when he reveals he returned to evil, how does he do it? He summons up a plate of cucumber sandwiches and throws it face-down on the ground. This especially hits close to home for kids or adults whose friends suddenly turn into jerks for unknown reasons causing the person who lost said friend to question if it's their fault
Seeing Celestia, Luna, and Cadance giving up their magic to Twilight. All three look broken and drained, and in a subtle move, Celestia and Luna's manes have been rendered static. When Tirek barges into the throne room, they don't even put up a fight as he attempts to drain them and then they get shunted off to Tartarus.
Twilight's reaction says it all - she's silently weeping when she sees all three of her mentors in this state. The hug she gives Celestia is enough to drive one to tears.
Ponies drained of their magic looking down where their cutie marks used to be. Seeing that cutie marks are a sign of adulthood for ponies, it's like they're being robbed of their own identity. Twilight looking down at Celestia's erased cutie mark and Luna and Cadance seeing their own gone as well provides an extra punch that not even they, the enlightened rulers of Equestria, are safe.
An underlying one. Much like Celestia's banishment of Luna, Scorpan tried to reason with Tirek and convince him to stop. In the end, Tirek refused and left Scorpan with no choice but to alert the Princesses and get Tirek sealed away. It isn't touched upon, but one can only imagine how that had to feel for Scorpan to be forced to do that. Even worse, unlike Luna, Tirek truly was evil at heart, meaning the two brothers are unlikely to ever reconcile.
Tirek and his brother Scorpan are never going to reconcile. This might be understandable in a sense, seeing as how Scorpan was part of the reason why Tirek got sent to Tartarus in the first place, but that doesn't make Tirek's disdain for his brother any easier to hear.
Discord: "But you said this was a sign of your gratitude and loyalty! A gift from someone close to you!"
Tirek: "My brother who betrayed me. It is as worthless as he is."
More heartbreaking is that Scorpan is seen wearing his medallion in the story sequence and it seems Tirek had the medallion during his imprisonment. This implies that Scorpan still wanted his brother to know that he still cared for him and gave him a token of their brotherly love. The fact that Tirek did at least kept it for long might indicate that Tirek never did get over the rift.
According to the My Little Pony Panel at San Diego Comic Con, one of the episodes is about Twilight mourning the loss of Golden Oak Library.