Accidental Aesop: Sort of. While it doesn't contradict the intended message of "Friendship isn't always the answer," the Jerkass behavior of the Original Characters in the story provide the addendum "... because some people are just assholes that won't even give you a chance to befriend them, and bothering with these people is a waste of time."
It is much easier to see Talon Ted as a narcissistic, manipulative sociopath than whatever it is Mykan is trying to portray him as. Considering this is his self-admitted Author Avatar, that's not necessarily a good thing.
Ath Lita was meant to be seen as an abusive sister who's apathetic to what her brother wants, dismisses his concerns and is borderline psychotic but a lot of readers saw her more as a concerned big sister who didn't want her brother to waste his life away and whose violent tendencies are more the result of being fed up with Talon's attitude. This got so bad, Mykan tried to revise the story so Ath came off as more unlikable.
Angst? What Angst?: Terra gets over all the trauma from being forced to betray her friends and the emotional and physical abuse from Slade pretty easily. Not to mention to the trauma of living homeless and starving for weeks. This is in stark contrast to the show's canon, where it's implied this angst was the reason she chose to live a normal school life instead of become a Teen Titan again.
None of the characters who are turned into Dark Angels in Darkness of Dimensions seem to have much of a reaction to being separated from their friends and loved ones and being turned into what are essentially demons.
Inherit the Sun sticks out here. So, Celestia and Luna are actually fooling every pony into thinking that they raise the sun and moon, and we are never given a reason as to why either. However, this trope really kicks in when one pony, a scientist, figures it out thanks to a pair of special goggles which somehow let him see through illusions and magic, published a paper about it, and is subsequently imprisoned thanks to some really unknown law about it being illegal to criticize Princess Celestia and friendship in general. Oh yeah, how do they learn this? Well, they go back in time using Starswirl the Bearded's time travel spell to the specific date when all this occurred, only, they are unable to interact with anyone because it is just shadow, which is clearly contradicted in canon, and when Celestia raises the sun, Starlight Glimmer somehow figures out that Celestia is just absorbing its power. To say that the entire fic's plot is built on this trope is not inaccurate.
In the final act of Love Doesn't Work That Way, Strings reveals he and Cadance are childhood friends and it's why he's in love with her. Despite the fact that all of the previous interactions with Strings and Cadance never even alluded to the fact they were friends (heck, their first meeting in the fic could fool you into thinking it was the first time they physically met), making it seem like Mykan came up with the backstory at the last minute.
Bill Dollar apparently has heart problems and ends up dying from a heart attack despite the fact this wasn't foreshadowedat all until the chapter where it happens.
In Beast Boy in Equestria out of plain nowhere, Terra is suddenly visited by her Guardian Angel and the Titans' computers suddenly become sapient in order to deliver Mykan's obligatory Author Tract and Exposition Dump. There's no proper explanation given for either.
In Hearth's Warming Eve Carol, Miser Stash is caught for lighting the tree on fire by flicking a cigar at it. Except it's later revealed that the tree catching fire was actually the result of an electrical fault that somehow went unnoticed amidst all the preparation work, just so that Miser can get off scot-free and not have to face any consequences for his jerkish behavior.
Many felt the ending of Darkness of Dimensions where the characters pull a Cosmic Retcon to stop the Dark Angels from existing was this becuase of the zero ammount of build up there was to this idea.
Big-Lipped Alligator Moment: Pride and Punishment has a moment where one of the main characters, Talon Ted, fantasizes about being in a Star Fox-esque adventure with some of members of the Mane Six. And no, this has absolutely nothing to do with the plot.
In Darkness of Dimensions, when the universe is rewritten, Beast Boy is never born and it's said that as a result of this, the Titans never became a team. It's said this is because of "Beast Boy's idealism" except that had nothing to do with the forming of the Teen Titans.
Creator's Pet: All of Mykan's Original Characters are treated as in the right in spite of their actions either being illogical or outright jerkish. Bonus points for Talon Ted and Stone Heart, whom Celestia scolds Twilight for trying to help them instead of calling them out on their deplorable behavior herself. More bonus points go to Helper Soul who Mykan admits is his favorite.
Let's start with the fact that Stone Heart has a cutie mark for being a bad writer despite the fact you only get cutie marks for things you're good at. Even Troubleshoes eventually realized he was good as a rodeo clown.
Twilight gets credited for being the editor on Stone's books despite the fact that editors aren't normally credited
Apparently, Stone Heart's writing was so bad, it caused a bunch of publishing companies to collapse and fail. One author's books selling badly isn't gonna destroy an entire company who likely have a bunch of other clients and writers.
Next, Stone Heart's books were proofread poorly yet publishing companies published them anyway, when in reality, a publishing company isn't going to publish a book if they don't think it's gonna sell.
In Beast Boy in Equestria, a group of robbers steal millions of dollars from a bank, and it is said that that money belonged to people who deposited that money in the bank. In actuality, the money in a bank belongs to the bank.
Bill Dollar dies from a heart attack during a surprise party despite the fact you have to be really old to die from pure surprise (even if you have heart problems). Helper Soul dies in a similar manner except without "surprise" as an excuse; it's simply "Broken heart, inner trauma and pain from his leg".
Both Needle Stitch and Helpers Soul get their cutie marks removed because their former friends (Rarity and Night Light respectively) helped them get them and they want nothing to do with them anymore. Ignoring the fact that such a thing would be impossible without some crazy powerful magic, even though they got their cutie marks removed, Needle (Or Manny in his new identity) and Helper are still able to do their respective special talents despite the show establishing that if your cutie mark is removed, your talent goes with it along with some of your personality. (As you can probably gleam, Mykan doesn't really seem to understand how Cutie Marks work in general.)
Talon Ted acts like being a famous actor without getting a degree is a huge accomplishment that no one has ever done before. In real life, there have been numerous successful actors who never got an acting degree.
In Darkness of Dimensions, Terra shows signs of getting pregnant one day after having sex with Beast Boy. In real life, it takes at least a few weeks before showing signs of pregnancy.
Designated Hero: Characters intended to be seen as the good guys who are instead interpreted by the audience as unlikable jerks at best and irredeemably cruel villains at worst is to be expected from Mykan.
Garfield Logan in HSM V: Ways of Life:
Another_Brony: He is just a jerk. He reacts with anger towards everything nice anyone may actually do for him and I don't get why Sunset and her friends should even bother helping him. Just because they are the good guys doesn't mean they have to be nice to everyone, especially if the other person obviously does not care for anyone or have one nice bone in its entire body.
He ends up as this earlier in Beast Boy in Equestria. If you've seen any of Mykan's works involving him, this should come as no surprise.
Talon Ted in Pride and Punishment is an ungrateful pony only concerned with his "pride", as well as completely brushing off his own sister no matter how nice she is. It doesn't help that Mykan has admitted him to be an Author Avatar.
Stone Heart in Write a Wrong is this for the same reasons as Talon Ted. When anyone has a problem with his stories, he brushes them off and pushes them out of his life like an immature brat.
The Dark Angels kidnap men filled with misery and take them away from their friends and family, force them to live a boring existence and not interact with anyone or anything even if it could save lives and are willing to declare war just because Twilight got upset that they took Spike from her (incidentally said war involves destroying everything and everyone)...and we're meant to assume they're heroes (at least initially) because they keep the "Darkness" in check.
Designated Monkey: A lot of these fics involve Twilight Sparkle and/or Starlight Glimmer failing a friendship problem, and some of these involve Rarity having done something in the past that she wouldn't have done in canon. #4 and #10 also continue the trend of Cadance abuse by having her being the cause of the very conflict and sad ending of #4, and in #10... well, it's not Overshadowed by Controversy for nothing.
Designated Villain: Ath-Lita is doing what she feels is best for a brother who simply refuses to do anything with his life due to his stuck-up "pride"... and we're supposed to be siding against her?
Twilight wants to save Spike from the Dark Angels and stop them from kidnapping others and taking them away from their friends and family...and we're meant to think she's in the wrong for this.
Ending Fatigue: Darkness of Dimensions somehow managed to have both this and an incredibly abrupt ending. The story takes its sweet time actually getting to the resolution to the main story but then when that resolution comes, it's over pretty quickly.
Ath-Lita for basically coming off as a Cool Big Sis towards Talon Ted (not that he appreciates it). It probably helps that the FIMFiction user/DeviantArtist she's based on, Cherry-Lei, is fairly amicable in real life.
Bill Dollar is probably the only one of Mykan's "failed friendships" that's seen as genuinely sympathetic due to being merely a shut-in instead of a total Jerkass. Doesn't stop readers from finding his sudden death any more Narmful, however.
TK becomes this in Darkness of Dimensions for calling Davis out on his bullcrap and acting like the Only Sane Man in the Digimon segments.
Esoteric Happy Ending: Pride and Punishment ends with Talon humiliating the Mane 6 and his sister and, after proving you don't need a degree to be a good actor by getting another pony to do it, decides to pursue his acting dream. The way the ending is played off is meant to be seen as Talon Ted inspiring a generation and moving on with his life except Talon is STILL the same stubborn Jerkass he was before and he leaves his sister in tears which is apparently "a fitting punishment for her overbearingness".
Family-Unfriendly Aesop: The overall message presented by the series is the rather cynical "Friendship can't solve everything."
Given what Beast Boy does in the story, the message of END OF ENDS!! seems to be "If the girl you like rejected you, emotionally manipulate and abuse her until she changes her mind".
Fashion-Victim Villain: Erebus, the leader of the Dark Angels, wears the same cheap black spandex as the rest of the angels, only his ensemble is even worse as he has antlers atop his head and long scarves wrapped around his wrists which just makes you think about how easy it is for him to trip over those.
Fight Scene Failure: All the fight scenes in END OF ENDS are poorly done and some involve the villains destroying everything while the heroes just... stand there and watch.
Hilarious in Hindsight: Beast Boy's counterpart turns out to be named Changeling. One deconstruction of Mykan's work featured Beast Boy, only to reveal that he was actually Thorax - as in, a changeling.
In Pride and Punishment, Twilight tries to help Talon Ted get past his stubbornness and help him realize how stupid he's being. And we're meant to side against her.
In Love Doesn't Work That Way, Strings is supposed to have a point when he says that he can't force himself to love Sun Rae but the way he words it makes him sound like a jerk who doesn't give a crap about his own best friend while caring only about his feelings towards Cadance. It doesn't help that Mykan has admitted we aren't supposed to be on Sun's side and that he only cares about Strings' well-being, not Sun's.
Bill Dollar is meant to be seen in the wrong for not wanting to reconcile with his family. Except said family was not only distant, but emotionally abusive. Sure, they may have realized their mistake but you can hardly blame him for not wanting anything to do with them and move on with his life.
In Fallout Fashions, we're presumably meant to see Manny Collars/Needle Stitch as being rightfully angry towards Rarity after she took credit for one of his designs. Except Needle GAVE the dress design to Rarity to do whatever she wanted with it and not only did Rarity apologize, she risked a major PR disaster by discontinuing said dress after Needle voiced how upset he was. Needle hates Rarity to the point where he not only banned her from his store but he also changed his identity to Manny Collars and got rid of his cutie mark just because she helped him get it. Overkill much?
In Darkness of Dimensions, Twilight is clearly meant to be seen as in the wrong for wanting to save Spike from his fate as a Dark Angel, considering she literally goes insane over it and it leads to the Dark Angels trying to destroy everything except Spike was taking from Twilight unfairly and since Spike is like a brother to Twilight, it's hard to get mad at her for wanting her family back.
It Was His Sled: Count Logan is Beast Boy. Just like the original End of Ends, the attempt to hide that fact is not done well at all, and anyone who's already familiar with Mykan's work will be aware of the twist from the get-go.
Unlike in the original The End of Ends, where they could be somewhat sympathetic due to their Undying Loyalty towards Logan and having their own unique personalities, #10 reduces Logan's minions to relatively generic mass murderers as they revel in slaughtering masses of innocent bystanders and gloating about it to the heroes.
Erebus crosses it when he decides to destroy everything and everyone simply because he feels the Dark Angels aren't being appreciated enough.
Nightmare Fuel: Say what you will about Count Logan, but the acts he commits in the tenth story are utterly horrifying to behold. Destroying everything and everyone was bad enough, but he takes the time to decapitate Flurry Heart!.
Overshadowed by Controversy: Friendship is Failure #10 has become infamous for Count Logan ripping Flurry Heart's head off. And the fact that Mykan had him do so not to demonstrate how evil Logan is, but because of his petty personal vendetta against Princess Cadance and to essentially get his detractors ticked off. He's also gone on record saying that he's more proud of this act than any other. It doesn't help that he did it again in Darkness of Dimensions.
The MLP sections of Beast Boy in Equestria, End of Ends and Darkness of Dimensions contribute almost nothing to the main plot and are likely only included in the stories so that Mykan could upload these fics to FiMFiction.Net.
Shocking Swerve: Bill Dollar's death comes right out of nowhere for the sake of having a failed friendship mission, with only the barest foreshadowing (the pain he feels in his chest) beforehand. Ditto with Helper Soul.
Changeling from Beast Boy in Equestria makes a LOT of creepy advances towards Raven.
Beast Boy kicking Robin in the crotch hard enough to dislocate his phallus and Raven subsequently having to fix it by putting her hands on said phallus is an image that both the story and the reader would have been wholly better off without.
Likewise with him ripping off Flurry Heart's head.Adult Fear doesn't even begin to describe it.
Strawman Has a Point: Many of the characters who are "supposed" to be in the wrong actually have really good points. Pride and Punishment is probably the best example of this.
They Copied It, So It Sucks!: Helper Soul has been criticized for having the exact same backstory as Master Org and still trying to pass Helper Soul off as a sympathetic character when the entire point of Org's backstory was to show how selfish he was.
A Hearth's Warming Carol could've been about helping Miser Stash get over his hatred of Hearth's Warming, which would've made for a much better Christmas Episode than a butchered retelling of "A Christmas Carol" with Twilight getting called out for absolutely no reason.
Ath-Lita in Pride and Punishment is meant to be seen as overbearing and trying to dominate her brother's life. She instead comes off as a sister who's worried for her brother's well-being and wants him to make something of himself instead of turning himself into a bum. It isn't hard to sympathize with her, especially considering that said brother is TalonTed. Granted, she does tend to beat him a bit, but frankly, who wouldn't?
Terra once again finds her way here. She's meant to be seen as in the wrong because of dumping Beast Boy in cold blood, but she goes through so much horrible stuff over the course of END OF ENDS, it's hard NOT to feel sorry for her, especially since a good chunk of that horrible stuff only happens because Beast Boy essentially guilt-tripped her.
Strings from Friendship is Failure #4 who lets his life fall into a depressing spiral which hurts his career because he loves Cadance who he can never be with and refuses to move on and find someone else even though he has a perfectly good alternative in the form of his friend Sun Rae who has an obvious crush on him.
Talon Ted complaining about his "pride" gets tiresome really quickly. There is literally a point near the beginning of the story where he plugs his ears and goes "La la la!" like a child in a conversation with his sister. There's also the fact that he is throwing away job offers because of the aforementioned "pride" when there are no doubt countless others who would kill for even a fraction of what Talon is offered.
Just like in his other fics, Mykan manages to get Beast Boy into this again. His endless whining on how he didn't get the girl and how "no one appreciates him" gets just as annoying as it does in those other fics.
Stone Heart in Writer's Blockade. he's yet another protagonist by Mykan who essentially refuses to let go of the fact that he Did Not Get the Girl. He even comes off a bit creepy towards her as he had been writing her into his stories and didn't understand why she was bothered by this.
Helper Soul. His endless bad attitude about how Night Light got everything he ever wanted and how it's Night's fault he lost his dreams gets tiresome.
What an Idiot!: In END OF ENDS, the monks of Azarath come into possession of the Dark Prognosticus, which is too dangerous to study but can't be destroyed by normal means. The logical thing to do would be to seal it away so that no one can use it, which they do... except the monks' seal has the caveat that it can only be opened by someone with extreme hatred and darkness in their heart. In other words, the kind of person most likely to become an Omnicidal Maniac using the book's power. And the kicker? You don't even have to be near the book to unlock the seal. You can be miles away and it will still unlock as long as you meet the requirments. How did anyone think that was a good idea?
In the same story, every time there's a scene where the bad guys have to win and destroy worlds, everyone just.... stands there... sure, they make an effort to attack, but after that fails they just go right back to standing there as millions of people burn. It's especially egregious in the chapter where Count Logan destroys Equestria where he kills four people right in front of everyone and nobody does anything!
As mentioned previously, Twilight often becomes this in the various stories. The poor girl just wants to help people and make their lives better and she's rewarded for this by being humiliated and talked down to, even by her own mentor, Celestia. END OF ENDS makes this even worse as her horn gets ripped off preventing her from doing her special talent and she's Forced to Watch her niece and brother die horribly right in front of her.
Princess Cadance also becomes this in Love Doesn't Work That Way and END OF ENDS. In the former, she's this for unknowingly being Strings' unrequited crush and forced to feel bad because he won't move on from her. In the latter, she suffers along with Twilight and is forced to watch her daughter and husband get murdered in front of her. Once again, all because Mykan hates her for being Happily Married while Davis and Beast Boy are not.
Sun Rae, also from the same chapter as Strings, is this because she had to fall for someone like Strings, a pony who won't even try to love her back because he's fixated on a foalhood crush that will never be reciprocated.
Terra becomes this very quickly in END OF ENDS. She just wants a normal life away from being a superhero and all the pain and trauma it entailed, but thanks to Beast Boy manipulating her, she becomes wracked with guilt for reasons she really shouldn't be guilty for and ends up being dragged right back into the very life that caused her so much pain.
Rarity is ultimately this in Fallout Fashions as she did everything she could to make up for her betrayal to her friend Needle/Manny but he still refuses to forgive her.
WTH, Costuming Department?: The Dark Angels in Darkness of Dimensions are pretty much guys in cheap black spandex... and you're meant to take them seriously!