* AnticlimaxBoss: [[spoiler:Apollo. He has all the makings of a KnightOfCerebus but due to his BondVillainStupidity he doesn't last as long against Godou as Mordred did when he faced Shirou.]]
* BrokenBase: The author's errors in regards to Nasuverse mechanics have split readers into several groups.
** There those who believe that the lack of research ruins the story.
** There are those who are a bit peeved, but decide that the mechanics themselves aren't really important to enjoy the story.
** And then there are those who are completely ignorant of how the Nasuverse works to begin with and just don't care.
*** And that's not even getting into the author's gratuitous use of {{Original Character}}s.
** With the reveal that [[spoiler:there is a statue of Sakura Matou inside Unlimited Blade Works]], some call it a sweet romantic gesture, others call it a boring cliche.
* HilariousInHindsight:
** In an early chapter, Hades attacks Shirou and says his wife Persephone had earlier been killed by a Campione, fueling his hatred of them. The author admitted to making that detail up for the story, then a later Campione! novel confirmed Persephone ''had'' been killed by a Campione.
** Rhongomyniad started out as a barely mentioned Noble Phantasm that had its properties invented by the author as a way of showing the many different versions of the tale of King Arthur. Come 2015-2016 side material, it has been confirmed as a Noble Phantasm that's A++ to ''EX'' Rank! He basically gave a weapon stronger than even Excalibur to Guinevere!
* JustHereForGodzilla: Many toxic reviews say Godou Kusanagi is boring and they don't care about him, wishing he would just go away and let the fic focus on Shirou Emiya, whom the reviews say is badass and the epitome of cool.
* TheScrappy: A lot of reviewers dislike Godou Kusanagi and consider him useless, since he hardly does anything on his own and mostly just reacts to whatever is happening. And whenever he does accomplish something or gets a power-up, the reviewers complain that he is just stealing Shirou's awesome moments.