History YMMV / SkulduggeryPleasant

** Kingdom of the Wicked's main conflict is about how Argeddion's plan to introduce magic to mortals is horribly misguided and naive, with Skulduggery believing that it will end in total catastrophy. Several books later, Until the End has the Faceless Ones bring the Shalgoth to rampage across the world, ensuring that mortals learn about mortals and their unique struggles in the worst way possible.

* Kingdom of the Wicked's main conflict is about how Argeddion's plan to introduce magic to mortals is horribly misguided and naive, with Skulduggery believing that it will end in total catastrophy. Several books later, Until the End has the Faceless Ones bring the Shalgoth to rampage across the world, ensuring that mortals learn about mortals and their unique struggles in the worst way possible.

** Mr Ping doubles as an EthnicScrappy and just plain [[UnfortunateImplications unfortunate.]] Mainly for sexually harassing Scapegrace. He disappeared after ''Last Stand of Dead Men'' and was never mentioned again.

* FanonDiscontinuity: The series' main [=YouTube=] reviewer, Capricioushelen likes to think of the Phase Two books as being set in an AlternateContinuity. Some fans are inclined to agree, feeling that Phase 2 tends to suffer from cases of [[AbortedArc plotlines being introduced and being discarded]] between books, several cases of TheyWastedAGoodCharacter and introducing many new characters, some of whom barely do anything, the rather dystopian overtones regarding the Irish Sanctuary [[note]]Such as police brutality, China's position as Supreme High Mage effectively making her a dictator, Skulduggery and Valkyrie's position as Arbitors making them above the law.[[/note]] and pacing issues that make things seem cramped and chaotic.

* Phase 2 was supposed to be 9 books but got cut down to 6, which does explain the pacing issues where it feels like it takes a while to get to the main plot while also trying to cram in a lot of ideas, and as a result ends up in a story that feels like it's trying to do too much. This problem already existed in Kingdom of the Wicked which takes a few chapters to get Valkyrie to the Leibniz dimension and then the story is about both a BadFuture where Mevolent won the war while also dealing with Argeddion's plan to introduce magic to the entire world while dealing with the 3 superpowered teenagers he chose to showcase his plan.

* FanonDiscontinuity: The series' main [=YouTube=] reviewer, Capricioushelen likes to think of the Phase Two books as being set in an AlternateContinuity.

** Was Crepuscular Vies's reason for leaving Skulduggery Pleasant justified or was it a case of him being oversensitive and willing to betray others for his own sake? He sides with [[Trumplica Martin Flanery]] yet chooses to mess with his head and eventually abandons him in favour of trying to make Omen into his apprentice while wanting to get back as his former mentor Skulduggery for leaving him to die.

*** [[spoiler: Bringing back Darquesse.]] Some feel it was needed and well deserved after the unsatisfying conclusion to their story in Phase One, while others feel they've played their part and outstayed their welcome, or that having something so powerful hanging in the background makes any active threats feel potentially pointless.

** [[spoiler: The Reflection/Stephanie.]] Obviously it would always be difficult to design a likable [[spoiler: ReplacementGoldfish]] who's an [[spoiler: exact clone of Valkyrie]] but her martyred, holier-than-Valkyrie attitude (despite [[spoiler: murdering an innocent girl]]) and her place as [[spoiler: new protagonist]] in ''Last Stand of Dead Men'', despite the fact that she has precious little impact on the plot, has led her to become rather unpopular. The fact that she [[KarmaHoudini completely escapes punishment]] for [[spoiler: the murder of Carol]] doesn't help matters.

* TheyWastedAPerfectlyGoodCharacter: The Man With The Golden Eyes. After multiple books of build up, he is shown to be genuinely regretful but unrelenting in his actions, putting him in an interesting situation with the heroes. Once his identity is revealed, however, he comes off as far less cunning going forward, and ultimately proves to be a spineless coward who abandons all redeeming qualities when things stop going his way. Of course, this does make a certain degree of sense, as like Batu before him, his threat lies in his secrecy and his being unsuspected. Once his identity is revealed, then he's in trouble.

** Valkyrie has become this in later books. Is she simply a brave, innocent and genuinely good-natured [[TheWoobie Woobie]] who wants to save everyone she cares about from her SuperpoweredEvilSide (and ask for nothing in return) and thus jokes around or snarks to distract herself, or an overconfident reckless [[{{Jerkass}} spoiled little brat]] who believes in [[ViolenceIsTheOnlyOption solving her problems by punching them]] and wants everything and sacrifice nothing, like wanting adventure and excitement with no concern for the danger she's putting herself and others in?
** Melancholia. [[spoiler: Was she driven crazy by Craven or was she always a homicidal maniac?]] Or did she just go ScrewTheRulesIHaveSupernaturalPowers?

** Is the reflection [[spoiler: just a mindless psychopath who killed Carol to gain power, or is she a pragmatic (she is ''Valkyrie's'' reflection, after all) human being who only wants the Sceptre to protect her family and her place in it?]]

** Valkyrie's trainer and ex Coda Quell is [[spoiler: unceremoniously killed at the end of "Dead or Alive" by an empowered Militsa, due to him having the misfortune of his murder attempt being on Féile na Draíochtha. He winds up falling into the death field [[ChekhovsGun set up earlier]], kiiling him instantly.]]

** Anything and everything about [[spoiler:Erskine Ravel]] after ''Last Stand of Dead Men.'' If you reread the scene in which [[spoiler:Ravel hits on Tanith in front of Ghastly]] in ''Mortal Coil'' and listen closely, you can hear the sound of shippers sharpening their pitch forks.

** The Monster Hunters basically have a "who would you do?" discussion about the Dead Men and Frightening Jones (without realizing that they're being overheard) in "The Malificent Seven". Frightening Jones is described as "gentle" and Vex's abs are admired.

** A chunk of the series has some of this starting out due to choice of names, though justified because everyone chooses their own name. The names "Valkyrie Cain" and "China Sorrows" sound more like Dick Tracy characters, but they make it badass. And the name Lord Vile sounds really Narm-y... [[spoiler: Then you get to the end of Mortal Coil and you see Skulduggery break down at the sight of him.]]

** This series is advertised for children 9 and up. This would utterly shock the people who have read the series without knowing this. Particularly in later books, given the amount of harm [[spoiler: Darquesse recovers from, including ''beheading''.]]

*** Even more so when you think about it. [[spoiler: Sanguine had a very creepy thing for Tanith for a while. Now, he's got an evil, possessed, ''fully consenting'' Tanith. God help the poor thing if/when she comes out of this stupor.]]

* TheyWastedAPerfectlyGoodCharacter: The Man With The Golden Eyes. After multiple books of build up, he is shown to be genuinely regretful but unrelenting in his actions, putting him in an interesting situation with the heroes. Once his identity is revealed, however, he comes off as far less cunning going forward, and ultimately proves to be a spineless coward who abandons all redeeming qualities when things stop going his way.

** Skulduggery getting trapped in the Faceless One's dimension between books 3 and 4. Although it does affect his behaviour, once Valkyrie gets him back, things return to normal a little too quickly, as if Landy just wanted to get on with the Revenger's Club plot but had to follow up on the cliffhanger.

** Scapegrace. At first all the stuff that happened to him was hilarious, because he was such a pathetic character. [[CharacterDevelopment Now that he's genuinely trying to become a good person]] (and succeeding--kind of), the things that he has to now deal with on a daily basis ([[spoiler:a sex change, sexual harassment]]) stop being funny.

** Omen Darkley has it bad during Phase 2. Suffering from neglect due to his parents caring more about his brother fulfilling the Darkley Prophecy, he often spends his time suffering from low self esteem and often goes unnoticed. Throughout the series, he's constantly trying to prove to himself and others that he's as every bit as capable as his brother in terms of heroism, often having to face enemies far stronger than him in situations that a boy his age shouldn't be exposed to.

* AcceptableTargets: "Dead or Alive" has the villain Rancid Fines, a snivelling, parasitic Nazi who is often the source of ridicule throughout the book. None of the main characters take him seriously and his boss even threatens him, asking him if he'd dare to act against him for being black.

* FunnyAneurysmMoment:

** Did Argeddion really think the people he murdered didn't "count", or was he just trying to delude himself into believing he could still be an ActualPacifist because the alternative was too horrible for him? Was him killing Walden D'Essai an accident or did his repressed anger, grief and guilt finally [[RageInducingSlight boil over]] after his alternate counterpart revealed the truth of his plan? Was Argeddion [[HorribleJudgeOfCharacter oblivious to the consequences]] of allowing [[HumansAreBastards evil mortals]] to use magic or was he simply in denial until Walden refused to cooperate?

** Did Argeddion really think the people he murdered didn't "count", or was he just trying to delude himself into believing he could still be an ActualPacifist because the alternative was too horrible for him?

* GeniusBonus: In Greek mythology, Lethe is both a spirit and a river famed for causing forgetfulness. [[spoiler:It's an early hint that Lethe is a false identity, created after Savant had his memory wiped.]]

* {{Narm}}:
** The spectacularly awkward and on the nose way Temper's skin color is established when he's introduced in ''Resurrection.''
-->'''Temper''': Well, I've always had trouble hating people because they're different than me. It's a black thing, you wouldn't understand. Or maybe you would. Could there be a brother hiding beneath that freaky mask of yours?
** Valkyrie's first meeting with her [[spoiler: future self]] in ''Dead or Alive,'' wherein they fly in and violently murder the person she was talking to hardly a few minutes after she [[spoiler: arrives in the future.]] Much later this is explained by some kind of psychic connection drawing them together, but in the moment their arrival is so sudden and brutal that you may just have to laugh.

** The King of the Darklands, otherwise known as [[spoiler: The Unnamed. Only briefly and vaguely alluded to in Phase One of the series as an ultimate evil, and Mevolent's former master, the King of the Darklands arises Phase Two after it's revealed that the new BigBad on the scene, Abyssinia, is both his daughter and the vessel for his power. At the end of ''Bedlam'', the Unnamed is resurrected in the body of his grandson, Caisson, and it was assumed that he would then become the BigBad of the remainder of Phase Two, being the central figure of the Darkly Prophecy that overshadowed the lives of Omen and Auger Darkly. Not so, as he vanishes after his resurrection only to reappear a full book later at the climax of ''Seasons of War'', where he proves to be little more than a sideshow to the return of Mevolent and his forces, and is killed off very abruptly after being ganged up on by a crowd of schoolchildren.]]

* TheUntwist: With the amount of focus and hints dropped towards the subject, it was utterly inevitable even in the early books that [[spoiler:Valkyrie's reflection would develop sentience, as well as turn out to be a budding psychopath.]]
* WhatDoYouMeanItsForKids:
** This series is advertised for children 9 and up. This would utterly shock the people who have read the series without knowing this. Particularly in later books, given the amount of harm [[spoiler: Darquesse recovers from, including ''beheading''.]]

** The King of the Darklands, otherwise known as [[spoiler: The Unnamed. Only briefly and vaguely alluded to in Phase One of the series as an ultimate evil, and Mevolent's former master, the King of the Darklands arises Phase Two after it's revealed that the new BigBad on the scene, Abyssinia, is both his daughter and the vessel for his power. At the end of ''Bedlam'', the Unnamed is ressurected in the body of his grandson, Caisson, and it was assumed that he would then become the BigBad of the remainder of Phase Two, being the central figure of the Darkly Prophecy that overshadowed the lives of Omen and Auger Darkly. Not so, as he vanishes after his ressurection only to reappear a full book later at the climax of ''Seasons of War'', where he proves to be little more than a sideshow to the return of Mevolent and his forces, and is killed off very abruptly after being ganged up on by a crowd of schoolchildren.]]

** [[ParentalNeglect Om]][[WellDoneSonGuy en]].