When we last left our heroes, Twilight's friends had all fallen under the influence of Discord and become their opposite selves: the honest Applejack is a compulsive (and transparent) liar, the generous Rarity is greedily obsessing over a boulder she thinks is a giant diamond, the fun-loving Pinkie Pie is a grump, the kindly Fluttershy is a Jerkass, and the loyal Rainbow Dash has run out on her friends. Equestria is doomed!*cue happy theme music*Twilight starts to call out Discord on not playing fair in his little "game" by removing the labyrinth prematurely; Discord points out that he never said the Elements of Harmony were in the hedge maze, and that Twilight misinterpreted his riddle and fell into his trap as a result. He stays around just long enough to mock Twilight and "the magic of friendship" before leaving to cause more chaos.Twilight finally has an epiphany about the meaning of Discord's riddle, and concludes that the Elements of Harmony are hidden where her first adventure with her friends began: Ponyville. She drags the others back to Ponyville, which is showing Discord's influence: among other weirdness, buildings are randomly floating, the dirt roads are turned into soap, and day and night cycle seemingly at random. The attitude of Twilight's friends (which is getting progressively worse) isn't helping things at all, especially when they decide to play keep-away with her copy of The Elements of Harmony: A Reference Guide.Twilight, her patience with her "friends" wearing thin, finally gets her hooves on the book, and finds the Elements hidden inside. She forces the Elements onto the others (with Spike acting as a hasty stand-in for Rainbow Dash) and heads out to confront Discord, who seems resigned to give the ponies a shot at defeating him. Twilight powers up the elements, there's a familiar glow of power, and...Nothing happens.Without the bonds of friendship, the Elements are powerless, and Twilight's former companions leave in a huff. Twilight, utterly dejected, finally falls under Discord's corruption; she despondently walks home through the surreal madhouse that is now Ponyville, convinced that her friends (and any hope of defeating Discord) are lost for good.
When Twilight gets home, however, she finds Spike in quite a state, nauseated from burping up countless letters from Princess Celestia. They're copies of all the friendship reports she's sent to the princess during her stay in Ponyville. Reading over them, Twilight is reminded of her lessons of friendship, which breaks Discord's corruption and inspires her to redouble her fight. Tracking down Applejack, Fluttershy, Rarity, and Pinkie Pie, she frees them from Discord's influence by using a memory spell to remind them of all their good times. When they find Rainbow Dash clinging to a cloud that she thinks is Cloudsdale, the five endure a harrowing aerial chase before finally returning her to normal.Once again, Twilight Sparkle and her friends are set to take on Discord, who fails to realize that they've broken free of his influence.
Discord remains smugly confident that the Elements of Harmony are still powerless, only to learn otherwise when they hit him head-on, trapping him in stone once more. Back in Canterlot, the bearers of the Elements receive much-deserved congratulations from Princess Celestia... as well as a new stained-glass window commemorating their defeat of Discord.*cue triumphant mu... ...network promos*
Tropes present in this episode (YMMV tropes can be found here):
10-Minute Retirement: When the Elements fail to work on Discord and her friends seem to be irrevocably corrupted, Twilight Sparkle is ready to throw in the towel.
Anti-Magic: The protective force field Twilight creates against Discord's telekinesis also turns the portion of the ground it lands on back to normal. Her own telekinesis still works inside it, allowing her to lower everyone, herself included, down to the ground.
Bad Liar: In addition to Corrupted Applejack, Corrupted Pinkie Pie turns out to be this. She's tries very hard to be taken seriously, and as such denies when she's having fun.
Pinkie Pie: This may look like it's fun, but it's not!
Batman Gambit: In a stunning display of foresight and contingency planning, Princess Celestia pulls one of these off again: It turns out that Twilight's letters to the Princess about friendship were not simply an attempt to get Twilight to loosen up, but that for the whole previous season the Princess anticipated that Discord might try to render the Elements of Harmony useless by breaking the bonds of friendship between the Mane 6. She then further anticipated that Twilight would be able to re-unite with her friends, if only given a push in the right direction. So when it became clear that Discord had not been stopped by the elements, Celestia sent all of Twilight's letters back to her, giving her the Heroic Resolve required to save her friends and defeat Discord.
Discord in Part 1 of the episode mentioned that the group were supposed to find the Elements "back where you began". As it turns out, the Elements weren't in the maze and instead, it was in Twilight's library.
The "slenderbunnies" (including Angel) from Part 1 show up to stampede over Twilight.
From the same episode, Pinkie Pie's love of the chocolate rain, enough to get one last mouthful before the mane six put an end to Discord's reign.
Bring It: Discord does this twice, standing still and letting the Mane Six have a free shot at him because he knows they won't work with the group's friendship shattered and wants to use them failing to break Twilight's spirit. It works just as he planned the first time but results in his defeat the second time, as they've rekindled their friendship, something Discord doesn't realize until its too late.
Buffy Speak: Twilight descends into this... mostly due to frustration.
Twilight Sparkle: Necklace, necklace, necklace, necklace, and... big crown thingy! All right, let's do this!
The first time the girls (and Spike) try to use the Elements, their poses are surly/apathetic versions of the way they posed when defeating Nightmare Moon.
A subtle one in one of the old "friendship reports": "And like the path cut through the orchard, there'll always be a way through" isn't from any episode, but it still recalls "Over a Barrel", where the solution involved a literal path cut through an orchard, and where the actual report contained a close paraphrase of some lyrics from Pinkie Pie's song, the same song that ended with "and there'll always be a way through." It's presumably the end of that episode's report, considering Pinkie Pie interrupted it.
Rainbow Dash lounging on a cloud and idly waving a hoof is a duplicate of her introduction in the premiere, except this time she doesn't care about anyone else.
When Discorded Fluttershy makes Spike, the "new Rainbow Dash", trip with her tail and he crash, she calls him "Rainbow Crash"
Crapsaccharine World: Discord's reign turns Equestria into this. While it looks silly on the surface, everyone seems to have gone insane and it's getting progressively more chaotic by the moment.
Cruel Mercy: Discord doesn't break or Mind Rape Twilight himself and leaves her be... so that the crushing weight of the situation she's in can break her slowly and more completely than he did to the others.
Darkest Hour: Carried over from Part 1. Discord turns Equestria into a World Gone Mad that's getting progressively worse, the Mane Cast try and fail using the Elements of Harmony to stop him, causing them to break up for real, and Twilight crosses the Despair Event Horizon and gets ready to pack up her bags and leave. Thankfully, things start looking up from there.
Deadpan Snarker: Twilight's frustration with her corrupted friends turns her into this even before she loses her color herself.
"We've got the liar, the grump, the hoarder and the brute. That just about covers it."
Discord sarcastically tells the heroes to "friend me" with their Elements of Harmony. He knows as well as we do that that's not what they do.
Twilight has to find her friends, subdue them, and then re-befriend them in order to purify them of Discord's corruption.
"I'm going to fight for our friendship!"
Deliberately Monochrome: Played straight for the viewers, teased in-universe. Upon arriving back in Ponyville, Spike notes that the corrupted ponies appear gray, and Pinkie Pie has a good laugh about her odd coloring after she's been redeemed. Yet for some reason it never occurs to Discord that the mane cast are a serious threat when they show up fully-colored again, just as Twilight didn't notice anything physically odd about them earlier.
Despair Event Horizon: After seeing the Elements of Harmony fail to work and her friendship completely shattered, Twilight Sparkle gives up hope. She was preparing to pack up and leave town before Celestia returning her letters renewed her hope.
Didn't See That Coming: Discord had planned for just about everything... except Celestia sending back Twilight's letters to break her Heroic BSOD, and that it was possible for her to reunite her friends. It's likely the former was something he couldn't expect while the latter was something he simply didn't consider possible.
Dramatic Irony: Played much more sweetly this time around in that it's Discord who doesn't know a key fact... in this case, that the heroines have broken free of his Mind Rape and can use the Elements of Harmony again... while the audience does. This makes his downfall due to that fact all the more satisfying.
Driven to Madness: All of Equestria after Discord takes over; Big Machintosh thinks he's a gopher!
Earn Your Happy Ending: Over the course of the two-part premiere, the Mane Cast has been broken and Mind Raped, Twilight driven over the Despair Event Horizon, and had their homeland turned into a chaotic World Gone Mad around them. Twilight has to literally fight and physically subdue her friends to turn them back to normal. In the end, they manage to pull together and put Discord in his place. They saved all of Equestria and got their happy ending, but they really had to earn it!
Eldritch Location: Discord turns Ponyville into this. He changes the dirt roads into soap, has several buildings floating in mid-air, the water is pink, the ground is painted like a checkerboard, and cotton candy clouds hover over the city yet only rain on half of it. The worst part? This is just the opening act.
Embodiment of Vice: Each member of the "mane 6" has been corrupted by Discord to represent the antithesis of their Element of Harmony:
Pinkie Pie represents cynicism
Fluttershy represents spite/cruelty
Applejack represents deceitfulness
Rainbow Dash represents betrayal and aloofness
Rarity represents greed and envy
Twilight Sparkle briefly represents severance and isolation
Evil Cannot Comprehend Good: Discord seriously underestimated the Power of Friendship, assuming he'd completely broken the Mane Cast's friendship beyond fixing. Because of this, he refuses to believe they did it until it was too late.
Evil Is Petty: If Discorded Fluttershy sees the opportunity to be a jerk, she'll act on it in a heartbeat.
Exact Words: Twilight protests when Discord removes the maze without giving them a chance to find the Elements of Harmony. Discord responds by pointing out that he never said they were in the maze. Meanwhile, the maze was certainly part of his master plan as he said.
Exposition Beam: Twilight undoes her friends' brainwashing by reminding them of all the good times they'd had together.
Face Hoof: Done by Twilight when Fluttershy asks Rainbow Dash if she can restrain her.
Fluttershy: Um ... I'm just wondering if it's okay if I hold you down against your will for a little bit?
Face Plant: Twilight plows face-first into "Tom" when trying to get her book back from the corrupted Fluttershy, Rarity, AJ, and Pinkie Pie.
Floating Continent: Discord suspends several buildings in Ponyville on top of floating islands in the air.
For the Evulz: Not just Discord, but also Fluttershy under her new mandate to be cruel. Applejack gets a bit like this, too, but more like It Amused Me.
A Glass of Chianti: Kid-friendly variation: Discord enjoys a chocolate milk of glass while lounging on his throne. (He conjures a glass, fills it from top to bottom with chocolate milk, and drinks the glass, leaving the chocolate milk intact.... which then explodes.) It's non-alcoholic, but his mannerisms give it the same effect as it was.
Glowing Eyes of Doom: Rather than just Twilight, the entire mane cast sports these when using the Elements of Harmony to put Discord back in his can.
Go Back to the Source: "Twists and turns are my master plan, then find the elements back where you began."
Heroic BSOD: After spending half the episode trying to stop Discord, Twilight is finally corrupted after the initial attempt to use the Elements against him fails and her friends' behavior proves too much for her.
Humiliation Conga: Discord's downfall. Not only is he defeated by the six ponies he'd spent the past two episodes viewing as inconsequential, he has just enough time before being Taken for Granite to realize that his entire plan has been completely undone and he was dead wrong about the Elements of Harmony, something that Applejack and Twilight told him to his face, but he didn't believe them due to his own manipulations involving both of them. Oh, and he gets his Oh, Crap permanently frozen on his face in the process. All this happens in under a minute. If you believe he's conscious in his stone prison, then he also witnessed the World-Healing Wave that washed away his chaotic kingdom.
It's Personal: By the time all is said and done, Discord has done everything he possibly could to make his confrontation with the Mane Cast personal. Case in point, Fluttershy insults him. Sure, calling someone a "BIG. DUMB. MEANIE!" isn't the worst thing you could call someone, but getting Fluttershy to say something insulting about anyone shows just how far Discord has pushed everypony.
Jerkass: All of the corrupted ponies, but corrupted Fluttershy deserves special mention.
Fluttershy: Hey, Twilight! What's soaking wet and clueless? Twilight Sparkle: Fluttershy, I've just about had enough... [Fluttershy dumps a bucket of water on Twilight's head] Fluttershy: Your FACE! [Fluttershy slams the bucket on Twilight's head]
Kirk Summation: Twilight gives one when confronting Discord, telling him that no matter what, friendship is worth fighting for.
Laughably Evil: Discord. While his Mind Rape and corruption of the ponies is all rather disheartening, his cartoonish antics and observations to whole ordeal leads to extreme Mood Whiplash. He celebrates his Near Villain Victory in the most childish and hammed up manner possible.
Leaning on the Fourth Wall: The Elements are hidden "Back where [The Mane 6] began." The Elements were hidden in a book in Twilight's library. Specifically, the book that was opened and read at the very beginning of the first episode. Back where they began, indeed.
Let's Get Dangerous: Fluttershy is able to catch up to Rainbow Dash when Twilight reminds her that the fate of Equestria is at stake.
Rarity: How in Equestria can she think that tiny patch of cloud is Cloudsdale? Applejack: The same way he got you to think that cheap rock was a bona fide diamond? Rarity: ...I thought we agreed never to speak of that again.
Made of Explodium: Discord's chocolate milk of glass. He drinks the glass, not the milk, and the leftover milk blows up when he tosses it aside.
Memento Macguffin: Twilight's letters to Princess Celestia from the first season help her recover from Discord's corruption. In a more metaphorical sense, the memories of their friendship help Twilight save the others.
Mind Screw: Every aspect of Discorded Ponyville, though it's to be expected.
Mood Dissonance: After her failed attempt to defeat Discord, Twilight sadly walks back to the library, her head hung low... while all sorts of madness goes on around her.
Near Villain Victory: The only reason Discord doesn't win outright is Celestia sending Twilight's letters back to her to break her out of her Heroic BSOD. Had that not happened, Discord would've won without question.
Never Say "Die": After the first failed use of the Elements, Discord declares harmony in Equestria to be "officially dead." It's hard to call the trope averted, though, since "is dead" is a fairly common expression for the end of a concept.
Nice Job Fixing It, Villain: At the end of part 1 when Discord gives everypony their horns and wings back. Discord gave Twilight the means to defeat him by doing this, as Twilight uses magic to bring her friends back to their senses and bring back the Elements of Harmony.
Nothing Can Stop Us Now: Discord gives one of these speeches after the Elements Of Harmony fizzle out when the Mane Cast try to use them on him and gets the mentality to go with it. Naturally, this comes back to bite him in the end.
Discord: Bravo ponies! Bravo! Harmony in Equestria is officially dead. Discord rules, Celestia drools.
Not Quite Flight: Unicorn Twilight Sparkle appears to use this when teleporting directly into the air and projecting the force field around her friends.
Oh, Crap: Discord gets a very satisfying one upon realizing that the Elements of Harmony will actually work this time and he's about to get put back in his can.
Only Sane Dragon: Spike is the only one who remains unaffected by Discord, and is the only one who retains some semblance of reason and sanity in the library scene. Not that it does him much good.
Out-Gambitted: Discord has destroyed all of Celestia's defenses against him via Impossible Theft and breaking her champions but she arranges his defeat by sending some letters.
Painting the Medium: During a pan of Ponyville in chaos, a pony runs along the edges of the frame.
Personal Chocolate Raincloud: Twilight gets one when she walks home sadly after her failed first attempt to confront Discord with the Elements. Discord was most likely invoking the trope in order to be a dick.
Pet the Dog: Subverted. After Twilight has been corrupted, lost all of her friends and is walking dejectedly through Ponyville, Discord seems surprised and concerned for a few seconds, making an attempt to cheer her up by saying that she should learn to have fun in her new home. When she walks away, still dejected, and says that it isn't her home anymore, he stops and looks after her for a moment. CueBig "YES!".
Reality Warper: Discord, obviously. Towards the end, he holds out a glass under some chocolate milk rain, which fills from top to bottom. A moment later, he then drinks the glass and throws away the milk. Which then explodes and the explosion makes things darker.
Rule of Symbolism: When Twilight is fully broken, a tear falls from her eye, leaving a small puddle in the shape of a broken heart.
Running Gag: Corrupted Pinkie Pie angrily declaring "I hate ___!".
Sarcasm Mode: Some of Applejack's bad lies veer into this territory.
Applejack:[after the day abruptly turns to night] Wow, I can see so much better now.
Sealed Evil in a Can: One of the few examples where the evil is not defeated outright, but put back in its can.
When Twilight complains about Discord not playing fair, he reminds her that he's the spirit of disharmony.
By the end of the episode, he also responds to Twilight's Kirk Summation with disgust and telling them to just hurry up because he has some chaos to get back to. Subverted, however, because not listening ended up getting him Taken for Granite. Again.
That Liar Lies: When Twilight wants to know where Rarity took the book on the Elements.
Twilight: Where is she? Where's Rarity? Applejack: Beats me! Twilight:Lies!
That Poor Cat: Lets out a yowl when Twilight begins fighting with her friends.
This Cannot Be!: Discord has this reaction upon realizing too late that his spell has been broken and he's about to get blasted head-on with the Elements of Harmony.
This Means War!: When Fluttershy calls Discord a "Big. Dumb. MEANIE!" and gets downright furious at the mere possibility of him winning, you know he's in for it.
Title Theme Drop: A very brief and understated one (it's literally just a staccato piccolo playing the intro) when Fluttershy wakes up Rainbow Dash.
Tragic Heroine: Twilight eventually becomes one herself after she turns grey from a failed fight against Discord. Fortunately, she recovers from it.
Transformation Is a Free Action: Played with. When the ponies power up the Elements of Harmony after reuniting, Discord just sits there on his throne not interfering, as he believes the Elements have lost their power. He's wrong, and he doesn't take it too wellwhen herealizes it. However, he did actively try to steal them prior to that; Twilight cut his attempt off with a quick teleport and a barrier spell.
Victory Is Boring: Subverted; Discord seems disappointed when Twilight Sparkle refuses to react to the chaos around her and simply gives up, only to cheer loudly as soon as Twilight is out of view.
Villain Ball: One would wonder why Discord doesn't realizes that all of the Mane Six were gathered back together again after Twilight helps her friends to recover from their Brainwashing. Not to mention that the previously discorded ponies were back to their original colors.
Twilight Sparkle: With friends like you, WHO NEEDS.........enemies?
Word Schmord: The brainwashed Rainbow Dash does this with "loyalty".
World-Healing Wave: After being used to turn Discord back into stone, the Elements of Harmony let off one of these to undo his chaotic reign. It takes the form of a pair of rainbows tracing a huge domed shell over Ponyville, and then letting off a huge pulse of light.
Your Princess Is in Another Castle: The Mane Cast are all back to normal, everypony is in a Group Hug... and bison ballerina dance across the foreground, indicating that there is still Discord to deal with. Twilight lampshades it.
Twilight: Maybe it's a little early for a group hug.
X Must Not Win: Where in this case, "X" refers to Discord. It's a major driving force for the main ponies, especially Fluttershy.