While certainly possessing affection for her Master, it's unknown how exactly Fran viewed her relationship with Caules. It's either she viewed him as the love interest she was denied in life, or the father figure Victor Frankenstein never was to her.
Artoria during Mordred's flashback. Did the former really not hate Mordred for who she was or did Artoria simply lie about how she felt as part of her Perfect King persona? Apocrypha fans who have never seen Fate/stay night or Fate/Zero before would likely be unable to tell. Fate/Grand Order seems to imply the latter interpretation is true, as during its first summer event Artoria was passive aggressive with Mordred at best, hostile at worst, but that's ambiguous due to the event in question having the Servant's various quirks and relationships Played for Laughs (such as also portraying Artoria's Big Eater tendencies to a comical degree).
There has been debate about Jeanne's growing feelings for Sieg. While the final episode has Laeticia state that any romantic feelings come from Jeanne herself, there's debate on how much Laeticia had to do with bringing them out in the open. While Laeticia says it was all from Jeanne, it is important to note that Laeticia does influence a bit of Jeanne's personality, so it its possible that Laeticia might of developed some amount of feelings for Sieg that rubbed off on Jeanne.
Mordred gets angry when being called a woman, but also gets angry if her feminine traits are downplayed and she is referred to as a man. While a case can be made Mordred is just being a Hypocrite, its entirely possible Mordred dislikes the assertion of being female because, during her time, being female would be seen as a weakness, plus the only woman in her life of note was an abusive mother. To her, people calling her a woman, even if they don't mean to say she is weak, belittles her since her biggest source of pride is being the heir of King Arthur, and its important to note that she says heir and not son or daughter. However, treating her as a man bothers her too, likely because doing so removes the fact that, gender wise, she is a woman. Thus, it could be argued that Mordred just wants to be seen as herself, without gender deciding who she is.
Americans Hate Tingle: Sieg was received okay in Japan, where he won a spot in a Top 10 Anime Characters poll in a Japanese magazine, and in general is looked at in a more positive light. However, Chinese fans absolutely loathe him, considering him having disproportionate screentime and considered a 'cardboard'. American viewers also aren't really as fond of him as Japan is, the most lenient opinion about him is that he's overall boring, otherwise they share similar loathing with the Chinese.
Angst? What Angst?: Astolfo's tenure being the Servant of Celenike is completely forgotten by himself and the story, even if she put him through severe trauma of being commanded to violate his knight code and murdering Sieg, once Celenike died, he's instantly back into his usual cheery guy self. Depending on how you view it, it's either the writers just completely forgetting about it, or it's part of Astolfo's character to have such a short memory term (being scatterbrained).
Sieg pulling out Astolfo's sword to deliver the finish blow in his fight with Karna. Up until that point, whenever Sieg had turned into Siegfried, the sword given to him by Astolfo had turned into Balmung, implying that the sword acted as a catalyst for him to use Balmung in combat. This was shown explicitly in the anime, and was never made to be any different in the Light Novel as well. Thus, when he did so to win his fight with Karna, it comes out of nowhere since Sieg had thrown Balmung at Karna and was dashing to retrieve it, only to suddenly have the sword on him. The only explanation that would make sense was that the sword turned back to normal because Sieg was running out of time to stay transformed as Siegfried, but this is never confirmed nor made clear. Even if this was the reason given it would still not make sense, as the sword would still have been where Balmung was since Sieg did not have it on hand. The way the scene plays makes it seem like they used Rule of Cool, and than realized they had made a mistake with how Sieg could win, and so hastily changed how his powers worked to justify his victory.
Sieg gaining access to Fran's two Noble Phantasm's, Blasted Tree and Bridal Crest during the final battle against Shirou. The story tries to justify this by saying that when Fran sacrificed herself to try and kill Mordred using Blasted Tree, she willed a piece of herself to become a part of him after Mordred killed him meaning that he gained the power to use her abilities when he was revived, and this is a result of her "will" actually being contained in the lightning that originally gave her life and runs through her body. While this is already pretty bad since her lightning reviving Sieg to begin with is questionable writing, the bigger issue is with how this fact isn't revealed until the fighting starts between Sieg and Shirou, meaning the ability literally comes out of nowhere to justify Sieg beating Shirou. Adding to the issue is that Sieg already got a power-up when he was given Siegfried's heart and could thus use his powers temporarily and with great cost to himself. It would have made more sense for Sieg to turn into Siegfried to win, or better yet turn into the Dragon Fafnir like he does in the end to defeat Shirou, but given he used all his Command Seals to beat Karna, Fran's abilities end up feeling like a last minute twist.
Awesome Ego: Shakespeare. Some of his actions throughout the story have left this impression on some fans.
Sieg is this for Western and Chinese fans. Some like him and consider him an interesting take on Nasuverse protagonists with a good arc that fleshes him out into a hero from the almost literal Blank Slate he started out as, but others think of him as a bland, badly-written character whose presence in the story is barely felt and takes time away from other, more interesting characters (most prominently, Siegfried himself), and keeps getting undeserved power ups from characters that don't even know him (most blatantly, Fran's sacrifice that somehow empowered him). Comparisons to the worst traits of Shirou Emiya are common. His pairing with Jeanne is also controversial—either it's enjoyable and similar to Shirou and Artoria's relationship, or it's forced and cringey. It's to the point that his voice actor Natsuki Hanae has promised to try and make Sieg as likeable as possible. On the other hand the Japanese like him well enough, to the point that he managed to score 6th place in a popularity poll held by the Newtype magazine.note Though thanks to the magazine's reputation among some circles, people call into question how accurate said poll was.There's also another camp that believes that Sieg as a protagonist could work and had potential, but the writer was unable to convey it well, so they depend for an eventual collaboration with Fate/Grand Order to unleash his potential.note Judging from the positive response to the Apo collab Inheritance of Glory, they were quite right.
Jeanne got hit with this as well. To some, she's a great character with moments to show for it such as her exorcism of Jack the Ripper. To others, they find her underdeveloped and somewhat bland when compared to Mordred. However, it's when she starts developing feelings for Sieg that some fans started to really have a problem with her character. The most common criticism being that her feelings for him feels contrived/forced due to a lack of chemistry and proper build up, with some also feeling that Jeanne shouldn't even be in a relationship considering her history. This is only made worse with how controversial Sieg is in the first place. It's telling that it's her appearances in Fate/Grand Order and Fate/Extella, both of which lack the presence of Sieg, that fans have little to no problems about her.note Fate/Grand Order actually still had Jeanne remember Sieg, but it was handled less like a romantic lover, more like a concerned big sister, so people are more okay with her treatment there.
Astolfo. One side of fans (especially on places like 4chan) has had a soft spot for Astolfo since day one, most likely because of him looking exactly like a cute, pink-haired little girl, and his earnest personality and relationship with Sieg won him other fans. Over time Hype Backlash ensued and there are a lot of other fans who consider him shallow Pandering to the Base otaku bait with an irritating and bratty personality, or who dislike him due to his overzealous fans.
Frankenstein, who went from The Scrappy to this. She first gained and still has a lot of hate for being a cute female, when Frankenstein's monster's hideous appearance was central to its story. Outside of her design, she's also disliked for how little she factors into the story, as she gets only a few skirmishes and two notable fight scenes with Shirou Kotomine and Mordred to showcase her ability, and then is one of the first Servants to die with very little elaboration on her personality (which is what saved Chiron and Achilles) and serves no greater purpose in the narrative aside from saving Sieg's life and giving him some extra power. The anime attempted to rectify this by giving her relationship with Caules more focus, and the reveal that she suffered just as much as the original Frankenstein's Monster and her Dying Moment of Awesome against Mordred managed to win her several fans.
Atalanta temporarily became this during the anime's run starting from the end of Jack the Ripper's arc. Since the anime cut out a lot of her POV of the event, which solidified why she took the stance against Jeanne, it made a part of the audience consider her an annoying, wasted character who wouldn't shut up about protecting children and dismissing their crimes just because they're children, with another camp claiming that they still could make sense about Atalanta's stance and blamed the anime for cutting her POV contents, mostly because they already read the light novel. However, after she turned berserk and then had a tearful death scene with Achilles, both bases reunite, re-appreciated her and she's once again averting the trope.
Better on DVD: Due to the serialized nature of the story and just how much the entire anime feels more like an extended movie, watching multiple episodes at once might feel more immersive than taking in each episode individually as standalones. Clearly, the distribution of the series took notice, as it was eventually released in the biggest binge-watching platform in the world—Netflix.
Complete Monster: Celenike Icecolle Yggdmillennia, amongst the morally ambiguous Yggdmillennia family, is the only one who absolutely has no moral compass. Celenike practices blood magic, sacrificing innocents, including children, which she takes great pleasure in. A sadistic dominatrix, Celenike keeps a dungeon in her spare time where she tortures those who cross her, or just those who catch her fancy for the fun of it. In between missions, Celenike will very regularly torture, rape and murder attractive young men, especially homunculi she deems "useless". Celenike also become fixated on her Servant Astolfo. After becoming jealous that he is forming a bond with Sieg, a homunculus who has formed an identity, Celenike snaps and uses her Command Seals to force Astolfo to gruesomely murder Sieg just to break Astolfo. Unlike her other family members and many other antagonists from the franchise, Celenike is motivated by nothing more than cruel lust and unrestrained sadism.
Ensemble Dark Horse: Toole, the female homunculus that Sieg saves on the battlefield, started to gain traction in the community particularly once she goes out her way to help Sieg rescue the other Yggdmillennia homunuculi. Her slight resemblance to Maiya Hisau might have something to do with it, as well as surviving a battle with Achilles.
Sieg/Astolfo is way more liked than the canonical Sieg/Jeanne, especially in anime, where Sieg and she for a long time interact Like Brother and Sister before Jeanne's feelings for him blossom while Astolfo's interactions with Sieg from nearly their first interaction practically reek of romance due to Astolfo's bubbly nature. And then there are the people who cut out the middleman and just make it a threesome.
And on Jeanne's side, Mordred's a fair bit more well-liked as a paramour, with their stronger chemistry and overall similarities and contrasts as characters.
Fran/Caules is one of the most popular pairings amongst the Servant/Master pairs and even went so far as to help redeem Frankenstein in some viewers' eyes.
Fetish Retardant: Jack the Ripper's original design◊ can be this to some people as she has the upper body of a child yet has lower body more fitting for a grown woman. Luckily her new and improved artwork from Volume 2 have fixed the worst of this by giving her a normal physique.
Fight Scene Failure: A complaint leveled towards the anime adaptation is that the fights are all way to difficult to watch and rely on extremely large and over the top angles and usage of colors, resulting in most of the fights being downright difficult to even tell what is going on. Notable examples include the fight between Siegfried and Karna, Sieg and Mordred, and Sieg and Karna.
As good of a premise the Holy Grail War is (a battle royale among seven Master-Servant pairs), it also bears the risk of having too many major characters for effective storytelling. The visual novel Fate/stay night takes 3 mutually-exclusive routes to fully explore all of its characters through the protagonist's perspective; Fate/Zero manages to keep a balance on all participants with more focus placed on Kiritsugu and Kirei but not before a 45-minute Info Dump first episode. The cast of Fate/Apocrypha is overblown with two teams, fourteen Servants and fourteen Masters on both sides plus Ruler plus Sieg. As a consequence, five Masters of Red are just extras, many Servants have as much background story as the Servant you draw from Fate/Grand Order gacha, and the lack of focus on characters is constantly brought up as a criticism on the show.
The majority of the criticisms towards Sieg are an extension of criticisms that other Fate main protagonists are criticized for as well.note Namely in that they can be somewhat bland and boring for some However, this is more prominent with Sieg because of the fact that his character development is simply lacking in comparison to other Fate protagonists such as Shirou Emiya, Kiritsugu Emiya and Hakuno Kishinami. Hakuno and Shirou actually outgrow their initial blandness to varying degrees in each of their respective stories or are given some manner of justification that is expanded after it is revealed, such as Shirou's Survivor's Guilt or the Shocking Swerve twists regarding Hakuno. Kiritsugu is also a firm Anti-Hero who stands apart from the other protagonists, making him very much a popular character. To put it one way; while all four are basic examples of seemingly bland characters for their medium that do develop over the course of their story, Sieg suffers from having the least amount of Hidden Depths and development, and thus comes across as lacking.
Values Dissonance is in play for great effects here: Mordred being the tomboyish daredevil and Shishigou being a manly man with Cool Shades and both of them being anti-heroic to a degree fit well with the Western tastes as opposed to Sieg's frail shape, rather androgynous look and being a straight-up heroic character which the Japanese couldn't get enough of, but it's not as well-received in the West.
Harsher in Hindsight: Seeing Mordred of the past and present showing many of her more likable traits would hit you in the feels when if you watch the very end of Fate/Zero, you realized that Mordred is among those bodies Saber is standing on.
Plenty of Sieg's moments with Astolfo, while either ranging from hilarious to incredibly touching, absolutely reek of this. Made more apparent in the light novel when Astolfo gently comforts Sieg while the other is suffering an intense panic attack from all his near-death experiences. There's also a moment where after an insensitive remark by Sieg results in Astolfo harshly slapping him they're very quick to reconcile with Astolfo claiming Sieg is his everything when Sieg says he can easily be replaced by another Master in the event he dies so that Astolfo doesn't have to die after him, and they actually end up sleeping and cuddling in the same bed together. More than once. And there's so much more where that came from...
There's a bit between Mordred and Semiramis though mostly on Semiramis's end and of the violent kind. After Semiramis poisons Mordred with her Noble Phantasm during their final battle and leaves her struggling to survive, she offers Mordred a chance to live and even get her wish if she kills her Master Kairi and "becomes [Semiramis's] knight". What pushes it into suggestive territory is that she says this while getting very close to Mordred before cupping her chin with one hand and smiling into her face. Even before that, the two repeatedly trade insults and physical blows more viciously than nearly any other Servants.
Iron Woobie: Caules is dragged into the war against his will, spends most of the time worrying for Berserker's well-being and believes he is not good enough to be her Master. And yet he takes it all in stride and still tries to find ways to be useful to his faction.
Jack the Ripper and Reika. Sure, they have some horrific backstories, but they are also really into killing criminals, or people they perceive as such.
Also applies to Mordred. While she is violent and abrasive, she was rejected by her "father" and had her dreams of being a perfect knight dashed. Not to mention being the pawn of her mother, Morgan le Fay.
Just Here for Godzilla: Long-time Fate fans mostly watch this series for their favorite Servants such as Karna, Mordred, Astolfo, Jeanne, Semiramis, or Achilles, not the plot.
Sieg, who in addition to his canon love interest Jeanne also gets shipped with Astolfo for their friendship (and the fact Astolfo's bisexual) and with Mordred for their Foe Yay and eventual rivalry.
Astolfo, who gets shipped with Sieg, Jeanne, Mordred, Siegfried...
LGBT Fanbase: Not surprisingly, given the presence in the work of characters such as Astolfo, who has an androgynous appearance and identifies himself as a bisexual, and Mordred, who can be perceived as a genderqueer because of her manliness and refusal to consider herself a girl yet still having little to no problem wearing Stripperific clothing.
Magnificent Bastard: Shirou Kotomine is a Church minister presiding over the Red Faction and is the Master of Assassin Semiramis. In reality, he is Amakusa Shirou Tokisada, Ruler Servant summoned in a prior Grail War. Noble and benevolent, his methods are ruthless and cunning. Seeking humanity's redemption out of pure love for mankind, Shirou bid his time, gathered items as catalysts to summon a Servant in the Middle East, and waited Yggdemillenia of the Black Faction to show themselves. Midway during the next Grail War, Shirou launched an ambitious attack that sees him singlehandedly take over the Servants of the Red Faction, reclaim the lost Greater Grail, and out-gambit his enemy Darnic. He intends to invade Greater Grail's innards to access True Magic to begin humanity's salvation. Ever calm and collected, it is only when he is minutes close to achieving his dangerously alluring dream that Shirou rants to Sieg not to ruin humanity's salvation.
Being Lancer Is Wonderful Explanation Both Lancers are ridiculously powerful and manage to score some impressive feats, unlike their previousco-classes. Even more hilarious considering that Darnic won the previous Grail War with 'Fionn', as the anime revealed.
Being Lancer is still suffering Explanation (Spoilers) In the second volume, Vlad is stripped of his advantage, forced to use his Legend of Dracula Noble Phantasm against his will, and possessed by Darnic; despite fairing well against a total of six Servants at the same time, he, a Catholic, is soon dispatched by Shirou Kotomine AKA Amakusa Shirou Tokisada, a Catholic pseudo-saint. And on the other hand, despite Karna's much better performance, he's still stuck with a Master that he doesn't fully trust, got his servitude via underhanded means, and having to take the antagonist role. For the camp that liked him and also disliking Sieg, they also put 'being eventually beaten by Sieg' as another point of Karna's suffering.
Who can Karna defeat? Explanation Due to Karna's ridiculous Story-Breaker Power and badassery, people are comparing him to various other Servants, particularly Gilgamesh, and argue whether not he can beat them somehow (usually it's a yes).
Fiore wants the horse D Explanation Fiore is shown to have a case of Bodyguard Crush towards Chiron who is actually a Centaur in human guise. There's also the fact that they repeatedly mention Chiron "proving his worth as an Archer despite his human form", which sounds really shady. Fans took this idea and ran with it.
Fiore is Doc OckExplanation (spoilers) Fiore's Mystic Code, the Bronze-Link Manipulators, manifest as five giant Magitek limbs that make her look like a cute female version of the infamous Spiderman villain.
Spartacus used SpartaKick!Explanation In Episode 9, Spartacus unleashes an epic kick on Atalanta that sends her flying quite a distance. Add in how Spartacus and Sparta are similar and the joke writes itself.
Spartacus and DOWN WITH OPPRESSION!!!Explanation Fighting against oppression is Spartacus' tricks of trade, and seeing that he's got Mad Enchantment, fans tend to think that Spartacus likes to yell anti-oppression things to define himself, defying logic all the way.
Cardboard-kun Explanation Since Sieg was quite controversial, at least in the Western side of the fandom, there are often times that there are memetic images which replaced Sieg with a cardboard, or put a picture of his face on a cardboard to emphasis their thought that he's as boring as a cardboard, which is also his Fan Nickname.
Won't someone think of the children!?Explanation Atalanta is VERY concerned on the safety of children, most people just think that this is her rallying cry, which sounds like something said on a soapbox
The Haunted Astolfo bean plushie that sucks your dick and calls you gay. Explanation A bean plushie of Astolfo sold as merchandise that is supposedly Exactly What It Says on the Tin.
Misblamed: The detractors of Sieg's character development (or just his character in general) blamed Yuichiro Higashide for the direction it took. However in an interview as early as 2013, it's revealed that Sieg's character arc was actually written by Kinoko Nasu himself.
Celenike crosses it as well. While in the midst of a Villainous Breakdown, she uses her Command Spells to force Astolfo, her Servant, into killing Sieg. Her reason? Astolfo was getting too attached to the homunculus he saved, and she intended to make him drown in despair him by making him break his code of honor by forcing him to murder an innocent person. She only saw Astolfo as her familiar, meaning in her mind, she owned him and can do what she wants with him, even break him mentally. For that matter, having a master like Celenike is any good natured and honorable Servant's worst nightmare.
Exclusively in the Light Novel, her first crossing can be seen when she was grumbling on how disobedient Astolfo was for saving Sieg in the first place. A homunculus passed by her torture room, merely being in the wrong place and the wrong time, and when Celenike noticed this, she ordered the homunculus to come inside the room... and proceeded to gruesomely murder that homunculus because she can.
In the very next episode, Avicebron/Caster of Black crossed it by sacrificing his own Master Roche to complete his Golem, despite his screams of anguish of being betrayed by his own Servant/professor, which subverts his reasoning to the Red Faction about defecting to them as long as his Master is unharmed, because he'll be the one who does the 'harming' personally, for his own goal of recreating Paradise since he dislikes mankind, and in his own words, it has nothing to do with the Holy Grail at all. So all along, he's on neither side. He seals it with his own words, "You have every right to hate me.", and now you see why the normally affable professor is amongst the more amoral characters in both factions.
As of Episode 23, Shakespeare using his Noble Phantasm First Folio to Mind Rape Jeanne. First, he uses his illusions to create scenarios, like her mother begging her not to go to war, or making her see the dead soldiers blame her for their deaths, but these have no effect on her. That is until the third scenario, where it is pictured almost exactly like the time she was burned at the stake, except, he makes it so its Sieg who gets burned. This effects Jeanne visibly, but she doesn't break. The final scenario, where her old friend and comrade in arms, Gilles de Rais shows up, with Seig's severed head, and gives her a massive Breaking Speech about how she really loves the poor lad, when she is supposed to a love everyone equally as Saint, while slowly transforming into his murderously insane self in the process. By the look of satisfaction on his face, Shakespeare probably knew the first two scenarios wouldn't work on Jeanne, but it did anyway simply to test her, before moving on to acts three & four to really break her spirit.
Narm: The anime adaptation has several unintentionally funny moments, whether it was because of the source-material, or the bad animations itself.
Celenike's out of nowhere Lecherous Licking on Astolfo, at least in the anime. There is literally no explanation for the two times it happens, and Astolfo's bored expression left many confused as to what even the scene was trying to do. Bonus point for fans who think it is gratuitous Yuri fanservice and later find out it is not.
Rider of Red's, Achilles, armor looks oddly too big for him in the anime, making him look absolutely scrawny and causing many to laugh at how silly he looks since it makes him look Off-Model. Thankfully this has been fixed, and his armor is now consistently fitting.
Vlad's Legend of Dracula is terrifying in how it transforms him and his Demonic Possession by Darnic is chilling, but get past that and one can't help but notice how he's like a Scooby-Doo villain with hammy dialogue (from Darnic), complete with scrawny arms, red pupils, and awkward bat wings. It doesn't help that the animation really doesn't convey how terrifying this is supposed to be, such as how Vlad's mouth effectively stops moving save for a small twitching, as if him talking was not possible for some kind of effects reason.
For native french speakers, the frequent inability of any character in the dub to correctly pronounce french names, such as "Jeanne d'Arc" or "Orléans," can make certain conversations difficult to take seriously, especially when it is Ruler herself who makes these mistakes.
When Waver is talking to Iskandar's catalyst, it's subbed as, "Heroes are those who do things driven by their ego. Like you, dude." It's apparently an attempt to convey a change in tone from the usual brusque way he addresses most people, but hearing the normally serious adult Waver say "dude" just clashes heavily with how character and can cause some unintended comedy.
Mind Screw is the story of the birth of Mordred, which was conceived between a Saber who turned into a man and her half-sister, who later turned a child into a clone of "father", can be quite amusing for some. The fact that the original Mordred was also a child of Surprise Incest does not help much. Despite this, Mordred is such an endearing character that if anything, her Mind Screw backstory makes her more likeable.
When Atalanta decides to use Agrius Metamorphosis to kill Ruler, the way in which her transformation is handled is actually pretty good, as the animators make it difficult to see her, but in a way that conveys how bestial she becomes. However, the moment the animation gives the viewer the chance to see her full body, all drama is lost for how silly she looks. Instead of taking on a monstrous form as you would think, she instead changes to a Stripperific outfit with a black boar head on her shoulder and her hair turns white. It becomes way more funny to see then it should be, making what should have been a terrifying form, into an edgy looking recolor of Atalanta. At the same time, it works because of how absolutely batshit and feral Atalanta becomes as a result, screaming out Ruler's name and moving around like she's two seconds away from trying to tear Jeanne apart with her bare hands, which when combined with appearance becomes both disturbing and strangely humorous.
Narm was inevitable when trying to put words into the mouth of William Shakespeare himself. Both the original Japanese and the dub make their attempts, but the end result is him spouting a few token archaic words and phrases from his plays, causing him to come across like a melodramatic high-school literature student desperately trying to sound deep. On the other hand, Shakespeare is supposed to be a Lethal Joke Character that most characters don't take that seriously until it's too late and he's more likely the origin of why people like those archaic words and hamtastic performances in theatre, so it makes sense that Shakespeare would chew the scenery with those whenever he appears.
The heroes plan for assaulting the Hanging Gardens of Babylon in the finale? An army of airjet liners. The sheer absurdity of this is both outright hilarious, but also provides the awesome Chiron and Achilles fight, and provides a nice change of scenery from the previous fights, making it work surprisingly well.
One-Scene Wonder: Gilles de Rais appearance as a Saber Servant is short-lived, but he doesn't fail to make an impression, bringing back the Ax-Crazy demeanor of his Caster-self in Fate/Zero, while also showing his more broken side and willingness to redeem himself, even sacrificing himself so Jaune can finish her prayer to use her second Noble Phantasm.
One True Threesome: Sieg/Astolfo/Jeanne is very frequently used as an alternative to shipping one or the other with Sieg. It helps that they all really care for each other by the end of the series. Siegfried and/or Mordred are also added in as extra members.
Rooting for the Empire: The show eventually had the Red Faction becoming the main antagonist faction. But there are just some that believed that they deserve to win:
First, the members. Shirou Amakusa is a Well-Intentioned Extremist whose end goal could be said to be admirable, Karna being an overpowered yet honorable Servant, Achilles being a sociable bro and also overpowered Servant, Atalanta for her very pure wish (and the tragedy that comes with it) and tough attitude and adorable cat ears and tails, Shakespeare for his ham in just about everything leading to hilarity even when he's the antagonist, and Semiramis for being a classy, sexy dominating queen with oddly adorable elven ears. Even their deserter, Mordred, gets a LOT of love due to her overall badass daredevil attitude and accomplishment that fans may also want her and Shishigou to snatch the Grail. While Spartacus might not get very high levels of love due to being eliminated early and unfortunately being considered 'wasted potential', his craziness and meme factor in his short run was also welcomed. While the original masters except Shishigou were reduced to props without personality, it's not quite considered a damning factor and instead wins the favor of the camp that believed that the best part of Fate series are the Servants, not Masters.
Next, the first half's members of the Black Faction. While we had Fiore and Caules as genuinely good Masters of the faction and Gordes' fault was just being a haughty jerk; it's worth noting that the leader, Darnic, was a former Nazi collaborator that consumed the souls of children (his way of dealing with Zouken might not be enough to cleanse those). And Celenike is a serial rapist with no redeeming features. And their last master, Reika, is a crazy serial killer who raised Jack the Ripper and responsible of the terror in London for a long timeNote Not to mention, Reika wasn't the intended master of Jack, her place was supposedly filled by magus (possibly under Darnic's command) Hyouma Sagara who attempted to use Reika as a sacrifice for the summoning that Jack killed him on spot and switched to Reika, who went crazy afterwards.. At first, this sets up for the show being Grey and Gray Morality to facilitate on rooting for the Red Faction.
A minor point but Shirou was originally a servant to an Einzbern homunculous and was distraught when the latter was killed by Darnic. Anybody who was fond of the other Einzbern homunculi tend to be slightly biased in favor of Shirou.
Next, the second half's members of the Black Faction. By that point, both Darnic and Celenike have been killed due to their own evil actions and Gordes had a change of heart, whereas both Sieg and Jeanne entered the faction, turning the Black Faction to be the more bonafide good guy team (Reika is eliminated in a latter time). This upsets people who were more into moral grayness and thought it was unfair that the Black Faction was cleaned up to be a less subtle good guys, and it didn't help that Sieg was the show's biggest Base-Breaking Character, furthering the desire for people to cheer for the Red Faction which was considered to have more nuances.
Finally, the Servants of the Black faction, while pretty good, have been much more of a mixed bag. Siegfried might be the one who would make the faction cool, but then he killed himself very early to revive Sieg. Chiron is overall pretty cool and his relations with Fiore was well-liked, but a lot thought of him as more of a supporting cast to Achilles' development. Vlad was cool on his run, but got the short end of the stick when Darnic forced him to turn into Dracula and then quickly eliminated by Amakusa. Avicebron committed a despicable treachery and struck down like a traitor that fans overall ignored him until he got a better showing in Fate/Grand Order. Jack's design put off a lot of fans and her role as a Serial Killer didn't help her. Frankenstein is a mixed bag overall. When Jeanne came in, people eventually got pissed with her budding romance with Sieg that she was considered ruined, leaving only Astolfo as the only cool Servant there, but even he had his own detractors.
Self-Fanservice: While it's fairly obvious Astolfo is supposed to look androgynous leaning towards cute girl, he still has some masculine features as seen in the manga adaptation and in the anime to some extent. You wouldn't be able to tell from fanart though, since it does away with those to give him a more overtly feminine appearance.
Squick: Jack the Ripper is dressed in very revealing clothing in combat, her lower half exposing her thighs and underwear in an uncomfortable amount of detail. While designs like these aren't unheard of, Jack's is especially detracting due to her likely being under 10 years old.
They Copied It, So It Sucks!: Many accused the epilogue, where Sieg meets Jeanne in the afterlife, of ripping off of Realta Nua's Last Episode, where Shirou reunites with Artoria in Avalon. As such, Apocrypha's epilogue is seen in a negative light among those who are fans of the Shirou x Saber ship.
There are many who feel this way about Siegfried. Siegfried quickly drew interest due to being one of the Black factions most powerful Servants, as well as having a fantastic design, being one of the first Sabers in the franchise to not be another Saberface. Fans also noted that his backstory and motivations drew more than a few parallels to Shirou and Archer, leading to many being interested in what his role in the story would be. Unfortunately, he willingly gives his heart to save the homunculus who would take the name Sieg in his honor by the end of the first novel before his character is fleshed out. The fact that he sacrifices himself for the sake of giving Sieg a power-up caused quite a bit of grumbling amongst fans.
Downplayed with Mordred and Kairi, as while they are main characters, their dynamic and personalities left quite a few fans wishing they were the true protagonists of the series rather than simply the Tritagonists.
Both Achilles and Atalanta at times got this about their characterizations. Achilles is usually accused of getting too much of a Historical Hero Upgrade, since a lot of his historical douchebag moments were not mentioned at all and he came off as a friendly bro-style character similar to Cu Chulainn, it was mostly accepted as awesome, but felt detached from Achilles' legend. In case of Atalanta, some feels like that her motivation about being children protector stemming from her being abandoned as a baby was something minor that got exaggerated, instead of her motivation being based from some of her other famous moments like joining the Argonauts or murdering her would-be suitors that lost against her in a footrace, distracted by the golden apple, and then getting turned into a lion. They instead went to her written backstories.
The premise of the story is basically: "What if the Grail War was teams?", and the first half of the story focuses on this idea for the most part by introducing both factions and having them fight each other a few times. Yet despite the setup and premise of a team deathmatch story for the Grail, once Shirou Kotomine steps up as the Big Bad, the story shifts to Sieg and focuses on only him, leaving almost all the other Servants and Masters aside from Kairi and Shirou as throwaway characters. And they really became throwaways come the final part of the story, where Sieg is the one who saves the day at the cost of most of the cast.
The idea of Shirou Kotomine, being an Alternate Universe version of Shirou Emiya that was raised by Kotomine and thus grew up to become a member of the Church, is an interesting idea that could have been used by the story to explore the ideas of an Alternate Universe that still has connections to the original story, while also providing a Deconstruction of Shirou's beliefs and actions. It would have been unique to have the protagonist of the original continuity face off with the protagonists of the new setting, and help develop the world more than it was already. Instead, Shirou Kotomine is the Heroic Spirit Amakusa Shirou Tokisada, meaning that the entire point of his name was a Red Herring to bait viewers. The real Shirou Emiya is only given lip service in the material books, having not gone through the same fate as his counterpart.
Given that the setting is an alternate universe that changes from the Third Grail War, you would expect the Founding Families of the Grail Wars, the Einzberns, Tohsaka, and Matou, to have a stake in the War or even have some significant usage. It would have been a good way to bring in old favorites like Kariya Matou and Rin Tohsaka. However, the events of the story make it so that the Founding Families can't get involved due to time constraints (the Association only has two months to prepare for the course of the War, too little time to get the red tape involving the Founding Families completed, which includes transportation costs and giving them time to prepare successors to their Family Crests in the event of potential death), so instead they need to hire on mercenaries they can afford to lose. This results in the Red faction being filled with five unnamed Masters who have no role what so ever, and two brand new Masters while the Black faction is also new characters. The anime adaption addresses this slightly by showing the outcome of the Third Holy Grail war in a flashback, revealing that Zouken is possibly dead, while Shirou Kotomine interacted with an Einzbern homunculus who looks nigh-identical to Irisviel and was most likely her predecessor as both the Einzbern Master/Grail vessel when he was summoned into the Grail War.
After taking over the Red Faction and gaining all the Servants of the Red Faction minus Mordred and a dead Spartacus, Shirou is confronted by Atalanta and Achilles who both question his motives and goals. While Atalanta accepts fighting for him out of necessity, Achilles shows disgust with Shirou and makes it clear he does not want to work with him. Given that his teacher Chiron is a member of the Black Faction, and that Avicebron defected to the Red Faction, thus leaving the Black Faction extremely underpowered, it would have made sense in character for Achilles to defect, or try to at least, and fight alongside his friend. Instead Achilles stays fighting for Shirou in-story out of a sense of honor and being at least partially impressed by Shirou's convictions and desire to see his wish come true. On a meta level, however, the reason for this seems more likely to prevent Karna from having anyone but Sieg to remotely be capable of fighting him, and to make the Black Faction the "underdog" of the two.
Early on it's made clear that once the two sides battle and one side remains, a miniature Grail War between the remaining Masters and Servants will commence. Initially, this is used (in the Light Novel at least) as a reason why Gordes refuses to reveal to the others Siegfried's name, and also why Astolfo's introduction causes the Masters to be surprised. Despite this being established very early on as a major part of the Black Faction's plans, it never comes up again for them. While understandable Shirou wasn't concerned, it feels as though the plot-point was used only to justify hiding Siegfried's identity from the reader and nothing else. None of the other Masters even remotely address it at all either, despite how strategic it would have been for some of them to avoid revealing their Servant's identity. The anime mostly just ignores this point as well.
Fiore's character arc in the series involves her developing into a leader for the Black Facation after Darnic is killed trying to obtain the Grail back, and the plotline is consistent for most of the series. However, on the night before the final battle, Chiron and Caules have a conversation and agree that she doesn't have what it takes to lead the facation as a Magus, and convince her to pass her Magic Circuits to Caules instead. This twist comes out of left field, especially after Chiron and Caules had discussed the issue before, and Caules agreed to help Fiore as much as possible, stepping up to be her lancer. Furthermore, Fiore's role just sorta vanishes after that moment, and she decides to give up on being a Magus even though she had gone along with it of her will and had shown herself being fairly capable. It feels like the entire character arc was just to make Caules develop at the expense of Fiore's own character arc. While it is admirable Fiore wants to go through rehab to get her legs working again, it comes across as a twist for the sake of a twist and feels necessarily forced.
Taking aside the fact that it's being made by the divisive A-1 Pictures, the Apocrypha anime gets hit with this hard when compared to the ufotable anime adaptations of Fate/Zero and Fate/stay night. Heck, it's even compared to the 2006 FSN anime and 2010 FSN UBW movie by Studio DEEN which some consider to be still better than the Apocrypha anime. It doesn't help that the story and characters of Apocrypha are considered lacking in comparison to FSN and Zero. It reached the point that several people were bashing Nasu himself for giving praise to the fight scenes in Episode 22, despite the fact that if anyone would be qualified to judge the series, it would be him.
The English Dub also has this issue. While the dub isn't bad, it comes after the dubs of the Fate/Zero and Fate/stay night [Unlimited Blade Works] dub, both of which are very well received by fans because of how good the voice cast was, with some replacements being certainly debated. Although the dub of Apocrypha is handled by the same company who did the previously mentioned two, the majority of the voice actors are mostly new, meaning that the voice quality ranges from great for some characters, to either not fitting well, or just outright weird sounding choices.
Viewer Gender Confusion: Many of the fansub groups portrayed Astolfo as a girl, incorrectly identifying his gender because of his feminine nature and very girlish voice. Though this is probably the intended reaction, it doesn't help some characters; namely Jeanne, are also confused and end up using female pronouns (which also caused translation errors, namely writing the subs for his correct gender!) The English dub attempts to avert this by having Faye Mata give him a more masculine, if still effeminate, voice. The Latin American Spanish dub completely averts this by giving him a male voice actor.
Visual Effects of Awesome: The fist-fight between Achilles and Chiron in Episode 21 and Karna's release of Vasavi Shakti in Episode 22 are visual orgasms.
Astolfo becomes this when his master, Celenike, uses her Command Spells to force him to kill his friend Sieg in an attempt break his spirit and sully his honor. Mordred killing Celenike is the only thing that saves Astolfo from this trauma.
After her Dark and Troubled Past, Frankenstein certainly counts as this. Literally the only good thing that happens to her is that she got Caules as a Master, he is the only one that treats her as a human being.
Atalanta's original life wasn't a walk in the park already (abandoned as a child in the forest, rejected by her peers because she's a woman, being forced to marry someone and setting up deadly footraces, losing due to being cheated by other Gods, then 'almost' turned into a lion), so she only had one simple wish: A world where children were loved... which turned out to be a Tragic Dream that was realistically unattainable, her mind gets wrecked by Jack the Ripper by playing onto her love for children, she fell into a mad rage and hate, especially towards Jeanne who could only give out blunt truths against her, and the only way out of that is death, which her friend, Achilles, delivered. In the last sane moments of her life, she was crying in regret of not knowing what should be done about the unattainable dream that deep down she knew, but couldn't let go. The hug Achilles gave her was damn needed.