Numerous plot twists are a trend that also dates back to the end of the Soul Society arc. It's revealed that the real reason Rukia's execution was arranged was so Aizen could get a powerful object called the Hogyoku that was implanted in her body. The Hogyoku itself didn't really get much build up beyond a vague mention in a letter, but because the story was still in its early stages and because it was important to the main villain's plans, most viewers didn't have a problem with it. Aizen himself was introduced as a kind hearted captain that was brutally murdered, before revealing that he had faked his death and was behind everything in the story to that point, a development that was widely praised at the time. Since then, the number of 'shocking' plot twists in the story has become perhaps the most common criticism about Bleach after Arc Fatigue, and every new twist tends to cause massive arguments in the fanbase about whether they make sense or not. This is most prominent during the Deicide arc, where Aizen becomes embroiled in a Gambit Roulette so ludicrous people stopped taking him seriously.
When Kubo kicked off the Soul Society arc, he more or less ditched the majority of the prior cast, and introduced around forty new characters, all of whom had distinct designs, powersets, and backstories. This worked extremely well, as it showcased Kubo's impressive skill as a character designer and a writer of Establishing Character Moments, with pretty much every new person to show up becoming extremely popular right off the bat. However, it resulted in the prior cast either not appearing or not getting that much development outside of one or two fight scenes. Fans waited for the Soul Society characters to get their dues... but then Kubo began the Arrancar arc, introduced another thirty or so characters, and gave them all distinct designs, powers, and backstories, while the Soul Society cast largely went into the background, only showing up to maybe get one fight scene. Then Hueco Mundo introduced another couple dozen characters, then Fullbringer, then Blood War... and by the end of the series, there were hundreds and hundreds of characters, and maybe ten of them had gone through any decisive Character Development. Thus the weakness was revealed: Kubo excels at creating characters, but he gets bored whenever he has to do anything with them.
The much reviled fourth season, SuperS, was founded on many of the elements people hated most about this arc: fairy tale inspired mythology, campy villains, a destined love between Official Couple Usagi and Mamoru, and spotlights on characters other than Usagi herself (namely Chibiusa). While all these elements worked wonderfully in previous seasons, by the time the fourth arc rolled around they just felt stale. The fifth season attempted to fight the Seasonal Rot by immediately sending Chibiusa back to the future, returning the series to magical sci-fi, introducing new characters for a fresh Love Triangle story, and making the Big Bad far more lethal than any previous season.
In the first two seasons, the villains's tasks were mostly resource gathering and direct invasion. The third season introduced plots revolving around minions targeting single random victims looking for a specific object. It worked fairly well in the third season, as potentially anyone with a heart pure enough could be hosting the Talismans, and in the fourth season, as anyone with beautiful dreams could be hosting Pegasus. Come the fifth season, however, this formula was carried on intact making the plot look idiotic: with Earth being the last unconquered planet in the whole galaxy, all the members of Shadow Galactica should have known a true star seed would only be carried by a Sailor Guardian. One would wonder why they attack random civilians instead of going after the Guardians when they showed up to fight. This renders much of the arc completely pointless and illogical until the final episodes.
In the El-Hazard: The Magnificent World OVA, Makoto's a Chick Magnet from day one, with three girls initially attracted to him, but it isn't really a Harem Series at that point. Makoto chooses his girlfriend fairly early on, and Nanami and Shayla-Shayla's attraction is a side plot occasionally tapped for humor and fanservice. But when they reach the third series, El Hazard: The Alternative World, the writers seem to have run out of ideas, and Makoto's girlfriend is on a bus anyway, so they have the girls fighting over Makoto every episode and insert a Third-Option Love Interest to spice things up. As a result, The Alternative World was widely seen as inferior to the first and second OVA series, and was Cut Short, with only 13 out of 26 episodes completed.
In the original version, problems that affected later parts of the series started showing up early on. Pacing problems were present since Skypeia, and the plot having way too many characters started in Enies Lobby. The Dressrosa Arc later became the pinnacle of both of these issues, with Oda attempting to cram too many new developments into one arc that resulted in: 2 and a half years in real life spent on the same island, about 10 extended flashbacks, a little over 50 named new characters, the reintroduction of several old characters, and 101 chapters of content.
Back in the Tower of Heaven arc, had Erza Scarletrequip to nothing but a sarashi and hakama pants, while dual wielding katanas, an outfit that is explicitly stated to not provide her any defense, or really any magic. What was supposed to represent her getting over her fear of pain associated with the Tower of Heaven and her own experiences with it became a predictable formula for all of her major fights from there on out: be on the receiving end of a No-Holds-Barred Beatdown, have most of her other armors either destroyed or disregarded, only to have her make a token 'Nakama Speech' and then reequip to this, resulting in a swift victory for her.
Natsu winning fights in ways that border on being an Ass Pull has been something criticized heavily in later arcs, but was evident early on, just not as extreme as it later was. For example, Natsu's fight with Jellal had him eating Etherium and getting a supermode that overpowered Jellal. However, this example came after the mechanics of Etherium were explained, and with it being made up of all the main elements, one being fire, it made some sense for the powerup to work for Natsu, and even after the arc ended, Natsu was sick because of it, implying heavy drawbacks for something as drastic as eating it. Later arcs however lack any attempt at using the powerups feel natural, such as have Natsu winning by pulling out random tactics that don't make sense yet somehow work out in the end, such as emptying his magic so he could eat Zancrow's Dark Fire God Slayer magic, even though Natsu couldn't do it before hand, something everyone present is just as surprised as the audience is. By the time of the timeskip, most of Natsu's victories are less him being creative, and more of him suddenly having a new way to win because the writer needed him too, resulting in fights becoming boring.
The sheer amount of fanservice later in the series got out of hand for many viewers, even though fanservice was a large part of the series. Early on the series used fanservice for subverting expectations, such as Lucy trying to seduce someone only to fail at it because either the person had their own warped sense of what was alluring or because the person was smart enough not to fall for it, or the fanservice ended up being poked fun at for existing in the first place, such as characters pointing out how silly it was for someone like Lucy to try to seduce people or Gray's stripping. Later chapters however began throwing fanservice out frequently with no reason beyond the sake of it, resulting in many scenes being ruined from either fanservice shots, or the characters doing something like randomly getting naked for "plot reasons". A notable example is during the finale of the Magic Tournament arc, when during the fight with the Dragons, Zirconis' dragon breath is able to strip people of their clothing. and he uses it on Lucy, only for Natsu to grope Lucy for a completely random and out of character reason, all for no reason beyond it was fanservice.
Characters seemingly dying, only to not actually die, was what ruined the final arc for many fans. This issue existed early in the series, but not as extreme. For example, Makarov was badly hurt early in the Phantom Lord arc, and was near death for a while during it, but the situation worked because Makarov was able to recover and be healed, thus saving the day in the end, and providing some good moments of action. The next few arcs had Erza, Juvia, and Makarov (again) all being near death and nearly dying, but for the former two, those were heartwarming moments tying into the character arcs for the two, while the later made some sense given it was during Laxus' attempted takeover of the guild, essentially suffering a stress induced near heart-attack. It was the Oracion Seis arc that this began to be an issue, with Jellal coming back randomly with a poor explanation for why, and the series just began to roll with it. Later arcs would constantly tease characters dying and than reveal them alive, such as Lisanna, Makarov (again), Frosch, the entire guild twice, and more. By the time of the final arc, almost every major character had a moment where it seemed they were going to die, only for the next chapter to reveal they were somehow alive.
Lyrical Nanoha's particular claim to fame has always been its superimposition of sci-fi mecha tropes over a MoeMagical Girl series, and for the most part this has been a good thing, allowing it to stand out from the crowd and earning it much of its fanbase. The problem, however, is that over time the franchise has shifted more and more into being a Magitek sci-fi epic, and the magical girl tropes were increasingly downplayed. This led to Magical Record Lyrical Nanoha Force, where the "Magical Girl" was dropped from the series title entirely, along with nearly all the magical girl tropes, in hopes of telling a sci-fi war story. In doing this, however, it lost sight of the particular formula that had made the franchise such a hit to begin with, and combined with some poorly-received characters, the series has been roundly criticized by old-school fans.
The manga's artwork was never particularly great compared to its brethren, and Kishimoto began to simplify it as early as the movement from pilot chapter to ongoing (Naruto swapped out his goggles for a headband because the headband was easier to draw). But it was still solid stuff, and the character designs remained lively and detailed. When Shippuden rolled around, though, Kishimoto gave many of the characters simpler and blander redesigns for the same reason, and the art became noticeably stiffer. The War Arc (when the manga's schedule was taking its toll on Kishimoto the hardest) saw this hit its peak, with some incredibly boring composition and lackluster fight scenes, which coincided with pretty much every other character wearing the same generic battle uniform.
The elements of Hard Work Hardly Works were there pretty early on, thanks to the entire plot driver being that Naruto carried the Nine-Tailed Fox and relied on its power to win fights many times. This was counterbalanced somewhat by the fact that relying on the Fox's power was often shown to be incredibly dangerous, and often caused more harm than good for him (with his ostracism being a big early conflict). But later arcs just kept piling on increasingly crazy details to make Naruto more amazing - he's the son of the Fourth Hokage and the prior carrier of the fox, he's the descendant of multiple noble families including the family of most prior Hokages, he's the reincarnation several times over of a guy who's basically the ninja Jesus, multiple people only choose to train him because of one or more of the above - which ended up turning him from a kid in a rough situation to a kid fueled almost entirely by his inheritance.
One of the biggest complaints Tenchi in Tokyo received was how most of the cast had become flanderized. This was also apparent in the show's much more well received predecessor, Tenchi Universe, but with much more restraint.
Mihoshi, the childish and simple minded galaxy poice officer deserves a mention. While she was never really that popular in the fandom, she was at the very least tolerated in the oringal OVAs, as she was had a few moments that showed that she wasn't completely ditzy. Later adaptations, however, played up her up her comedic elements to the point that her only purpose was comedic relief, causing her popularity to wane considerably.
Jojos Bizarre Adventure: One of the biggest reasons JoJo's Bizarre Adventure: Diamond is Unbreakable was considered an Even Better Sequel was its willingness to experiment with what a Stand could do and be, allowing for strange, unconventional, and unique fights that almost never degraded into the punching matches legion to shounen. A Stand that drained your blood from miles away, or comprised an army of tiny soldiers, or turned people into books all led to memorable setpieces and encounters. This experimental attitude to Stand design escalated with time - but by Stone Ocean, the widespread opinion was that Stands had become so unconventional and ridiculous that they headed right into nonsensical, with Heavy Weather's "create theoretical weather pattern of rainbows that causes people to think they're snails, which causes them to turn into snails" being the last straw for many, and frequently fights were so consumed with figuring out what a person's Stand did that there was very little actual fighting going on in favor of having the protagonist figure out an equally nonsensical solution.
Most of the criticisms of the second half of Yu-Gi-Oh! 5D's, widely acknowledged as a major step down from the first half (promising plot arcs being resolved inadequately, Konamibutting in where they don't belong, out-of-place goofiness, focusing on Team Satisfaction characters and Yusei in particular to the exclusion of everyone else) could be found to varying degrees in the earlier Dark Signer arc and even the Fortune Cup arc, widely acknowledged as two of the pinnacles of the franchise. The debate is ongoing as to how the drop happened, but the easiest answer would probably be that the earlier arcs had strong serialized plots with good pacing and high stakes that kept the audience interested despite their flaws. Meanwhile, the second half started off with thirty episodes of nothing important to the the plot, then transitioned into forty episodes of a consequence-free Tournament Arc, making the show's growing problems with characterization, tone, and plotting hard to overlook.
A common point of mockery, particularly against later installments, is the insane amount of Anime Hair and Impossibly Cool Clothes. This has been a part of the franchise from the beginning; Yugi's tricolor spiky hairdo is practically an iconic example, and Kaiba's exaggerated Badass Longcoat is similarly notorious. It sorta worked back then, though, because Yugi was the only major character to have much in the way of Anime Hair, and even that was largely the result of Art Evolution, and the character designs, though over-the-top, at least looked nice. By the time of Yu-Gi-Oh! ZEXAL, though, literally every character has at least two hair colors, a ridiculous hairstyle, and an equally ridiculous outfit, and the whole thing moved so far into ostentatious character design that it turned out looking downright ugly.
The idea of the protagonists always being able to draw what they need is one of the oldest in the franchise; its entry on The Magic Poker Equation is downright monolithic. Good "drawing skill" being an explicit ability was implied or outright stated of many characters, with "trust in your deck, and it'll come through for you" being a common moral. Cards with ridiculously specific abilities being used to counter an opponent's strategy and never being played again had been showing up regularly from the beginning. And in some duels, protagonists would use supernatural abilities to play or create cards that there was no possible way they could have had before. It was when all these things were combined in Yu-Gi-Oh! ZEXAL into the Shining Draw ability, which allowed Yuma to turn the cards he'd drawn into whatever he wanted, that fans really started to complain, as it took all the complaints about lazy writing, predictable outcomes, and unfair advantages and turned them into an explicit superpower for which the protagonist is constantly lauded.
Yu-Gi-Oh! ARC-V's later seasons, among many other things, were criticized for gratuitous and poorly-executed Continuity Nods, poor pacing and wasting episodes on plot that goes nowhere, preachy and inconsistent messages, and bad usage of its cast (especially its female characters). All these were present to varying degrees in the first arc, the only one uncontroversially regarded as good - cameos from older archetypes were thrown in willy-nilly, the "Yuya trains with Nico Smiley" arc is somewhat longer than it needs to be while the Maiami Championship arc is very stop-and-start and laden with rushed or barely-seen battles, the entire second quarter is made up of very obvious morality plays about the virtues of entertaining, and the supporting cast won infrequently while the female leads's only onscreen victories against male characters were when the latter had no idea what they were doing. These flaws were forgivable because not only were they not as prevalent, and forgivable as Early Installment Weirdness that the show could hopefully grow out of, but they had an intriguing mystery story wrapped around them that seemed laden with potential - and when the show didn't grow out of those flaws or live up to its promised potential, they became impossible to ignore.
Considering just how wholly loathed the concept of "legacy characters" became as ARC-V went on, it can be easy to forget the initial response to the revelation that Jack and Crow would be appearing, and their early episodes. In said early episodes, they even hit a lot of the major complaints - their appearance is fairly gratuitous, their personalities come off as arguably redundant in the cast, and they handily beat the show's own established characters. This was forgivable to many because of the assumption that their appearance would be confined to their arc, and that the focus would quickly fall back on the show's own characters. When they did not, and the show merely introduced more legacy characters to eat up screentime and had them staying prominent and getting Duels all the way to the second-last episode, the whole concept became something of a collective Creator's Pet for the franchise. Furthermore, while Jack and Crow were more-or-less dead-on to their Yu-Gi-Oh! 5D's counterparts, the later legacy characters were all much less accurate, leaving them much less of a fanbase. There were also initial theories that their appearance would be to justify some future plot points or even reveal a larger timeline or links to the other series - as it turned out, this wasn't true, and their appearances turned out to serve no purpose at all aside from nostalgia. The concept went from people claiming that the series had finally saved Crow to them dreading the appearance of Jack Atlas.
The Shadow Realm is an infamous example of Never Say "Die" in dubbing, but its effects on humans involved monsters tearing your soul to shreds, making it a case of Deader Than Dead. Since the anime also had a World of Darkness where Shadow Games took place and the Realm's effects were similar to the manga's horrific elements, this was easier to let go at the time—but when GX used euphemisms like "sent to the stars" without informed lethality it was easier to see it as Never Say "Die".
It's considered pretty normal in Digimon for only a handful of characters (typically The Hero and The Lancer) to reach the highest stages of evolution, going back to the original. From the beginning, this tended to create Spotlight-Stealing Squad tendencies, because it meant that battles often hinged on whether The Hero and The Lancer were there - but this was still kept in check, because the nature of Digimon (where assuming higher stages wears the Digimon out) meant that those superpowered stages were frequently either out-of-commission, and usually their teammates weren't so far behind as to be useless. But in Digimon Frontier, not only were Takuya and Koji the only ones to reach the highest stages, and not only did they take the lead from their teammates very early on (Zephyrmon, the final evolution obtained by anyone aside from them and Kouichi, shows up sixteen episodes into a 50-episode series, when Takuya and Koji still had three stages each to go), but the last stages of their evolutions involved everyone else lending them their power. It was one thing for them to be stronger, and another for them to be stronger and also literally make everyone else useless.