* AlternativeCharacterInterpretation: Is David a WellIntentionedExtremist who only [[ShootTheDog shoots the dog]] for the sake of humanity? Or is he an unrepentant KnightTemplar [[FantasticRacism fantastic racist]] who only kills Chiropterans for the sake of revenge?
* BrokenBase: [[spoiler: Diva's rape of Riku]]. Some fans declared that the series was RuinedForever and gave it up; others said that this was when the show started really picking up.
* CompleteMonster: While Diva, the EvilTwin of heroine Saya has her share of crimes, the true monster is her [[DragonInChief Chevalier Amshel Goldsmith]], an unscrupulous MadScientist who values Diva solely [[ForScience for his scientific curiosity]]. Amshel's experiments with Joel Goldsmith helped to turn Diva into the AxCrazy creature we see in present. Amshel handles most of the planning for Diva's team, and has no compunction killing anyone he thinks is a threat, even Diva's own Chevaliers. Amshel's actions lean to numerous deaths from the Chiropteran outbreaks and when Diva is dead, all Amshel cares about is stealing her baby daughters to experiment on later.
* CompressedAdaptation: The manga changes a lot from several characters. Saya is often a JerkAss, Hagi is more sensitive, Kai is more mature early but acts like a pervert towards Saya, Riku gets more screentime, David gets less screentime, Solomon is more like Amshel, etc. The plot and pacing also differ greatly from the anime. These changes make it look as if they were aiming to attract more male readers due to the bigger focus on bloody action scenes and added Fanservice.
* CrowningMusicOfAwesome: [[http://www.youtube.com/watch?v=uWVlB5LrPS8 "Diva"]].
** [[https://www.youtube.com/watch?v=u8CVSZzynGk Saya's Victory]], rightfully placed amongst the Greatest Battle Music Of All Times.
** [[http://downloads.khinsider.com/game-soundtracks/album/blood-complete-best/09-blood-grand-theme.mp3 Blood+ Grand Theme]] certainly qualifies.
* DesignatedHero: In the two manga series Saya comes across this. When she remembers her past she blames Hagi for abandoning her even though she took down his armchopped off his own arm. Saya's intention to kill everybody from her race are revealed earlier and Riku is simply told to deal with it. In both manga series, the climax has Saya brutally murdering an AntiVillain.
* DracoInLeatherPants: Diva, holy shit Diva. Both fanboys ''and'' fangirls give her far more sympathy than she deserves, given that while she might have a good FreudianExcuse, she is also incredibly ruthless and often needlesly cruel. [[spoiler: And a rapist/murderess who never shows any regret for raping and killing Riku.]] This is sometimes paired with them [[RonTheDeathEater villainizing and bashing Saya]], and more frequently with trying to excuse away Diva's evil deeds due to her DarkAndTroubledPast.
* EvilIsSexy: Diva again!
* GrowingTheBeard: When Saya grows her hair out. Possibly not the most accurate timing as that is subjective but things did seem to get more interesting around the time she was reintroduced with her hairstyle changed.
* HoYay: Nathan and James, Moses and Karman, and Karl and Solomon in the anime, Riku and Charles, and Hagi and Nishi in the prequel manga.
* MoralEventHorizon: Diva crosses it when she [[spoiler:rapes Riku so that she can bear his child, and then kills him]].
** Van Argiano [[spoiler: and the American government cross it when they plan to turn people around the world into Chiropterans and then choosing who to send TheCavalry to, effectively control the world.]]
** James Ironside crosses it when he [[spoiler: tricks Moses into hunting down Kai with the false promise that he can cure him and his friends of the Thorn.]]
* NightmareFuelStationAttendant: Diva, '''and how'''. In addition to being [[spoiler: the polar opposite of all things Saya]], she's an AxCrazy PsychopathicManchild who seeks nothing but the total destruction of mankind. Her antics as an [[ImplacableMan Implacable Girl]] toward [[spoiler:Riku]] do not help matters at all.
* NoYay: Diva/Riku. First, although Diva looks sixteen, she is really over 150 years old, while Riku is supposed to be fourteen but looks a bit younger. Second, Diva's obsession with Riku is just plain creepy. Third, there is the fact that [[spoiler:she rapes and kills him]].
** Saya/Young Hagi. In the flashback, she innocently tells him to help dress her, and, later, he says he'll even be her "friend" at night if that's what she wants. Keep in mind that he is only twelve at the time, while she looks sixteen and is really in her forties. Not so much of a problem once he gets older, though.
* UncannyValley: Diva's appearance during the second half may be adorable but her similarities with Riku are there to bring back NightmareFuel.