History YMMV / KamenRiderOutsiders

** Smart Brain, along with the Orphnochs being targeted by Zein if taking Mari's statement in episode 0 into account becomes this following Film/KamenRider555ParadiseRegained, wherein Orphnochs are being wiped out by Smart Brain themselves and replaced by androids.

** Yuichi Nakamura once photographed himself dressing in a green bodysuit [[https://twitter.com/NvKknpbmkIbDg6m/status/1313856693285969920?t=M915saaVS5rFtPX9os7dxg&s=19 wearing all sorts of the Heisei Riders' transformation devices strapped to his being during his 33rd birthday]], as a parody of AllYouPowersCombined forms. Lo and behold, he portrays [[spoiler:an alternate universe]] Yuto Sakurai, who transforms into a Kamen Rider with access to past Rider powers.

* IKnewIt: At least some fans correctly guessed that somebody from ''Geats'' would eventually be showing up in this project, owing to the fact it's the third Rider show written by Yuya Takahashi. Sure enough, Tsumuri is the {{Deuratagonist}} of episode 5.

** Kousei Amano would make his debut in ''Franchise/SuperSentai'' as [[spoiler:[[Series/OhsamaSentaiKingOhger Glodi Leucodium]] just one week before episode 4 of ''Outsiders'', where Garren King Form makes its live-action appearance.

*** In universe, the [[HeroAntagonist heroes]> believe that Zein is a [[BigGood paragon]] for all of the heroic Riders [[spoiler:that wants to protect humanity and eradicate evil.]] While the [[VillainProtagonist villains, former and current]], revile it [[spoiler:as a [[KnightTemplar malevolent destroyer]] with a DarkMessiah complex and radicalised sense of justice]] who will end humanity's malice because it will end humanity.

** Kamen Rider Zein's gimmick of shredding Rider Cards is both cool and [[FridgeHorror horrifying]] in the show. When his [[Series/KamenRiderGotchard Chemy card]] gets introduced as part of [[https://t.co/gb9TIT3qtE the voters' choice]], Zein is represented as a cartoonist paper shredder with a mechanical hand, of all things.
* HoYay: A carry over from their interactions in ''Saber'', both Desast and Ren's interactions in ''Outsiders'' takes bromance in ''Kamen Rider'' to an entirely different level. The fact post-CharacterDevelopment Desast had to part ways with Ren to avoid getting roped into the Ark/Zein conflict coming across as forcing one's lover out of harm's way.
* IKnewIt: At least some fans correctly guessed that somebody from ''Geats'' would eventually be showing up in this project, owing to the fact it's the third Rider show written by Yuya Takahashi.

** [[spoiler:The Yuto Sakurai from an alternate BadFuture where he has lost everything; with the fates of the Airi and Deneb of his timeline never elaborated upon. Coming into the present day as the host for a despotic artificial intelligence to become its enforcer transforming into Kamen Rider Zein. This Yuto was nearly an inch away at murdering both Horobi and the Ark which by doing so could've [[MoralEventHorizon sent him to full-blown villainy]] had Brain not interfered. Unfortunately for him, Zein possesses Yuto after Tachibana/Garren destroys the Ark, rendering Brain's pleas moot.]]
** Horobi also qualifies, especially for all the morally dubious deeds he's done in ''Zero-One''. He's the only member of [=MetsubouJinrai.net=] to be revived as part of Project Outsiders, only to defect to Zein's side, believing it as a paragon on justice. He gets subjected to humiliating defeats at the hands of villains who are potential candidates for said project, and finds out too late that he placed his blind faith on a [[TheComputerIsYourFriend tyrannical A.I.]] that wants nothing more but to rule humanity with an iron fist.
* LikeYouWouldReallyDoIt: Episode 4 saw the Ark being unceremoniously finished off by Kamen Rider Garren King Form. However, [[spoiler:as the teaser for episode 5 shows that the Ark manages to turn up okay, having barely escaped into the Internet like Banno did in the prior episode]].

* MoralEventHorizon: Zein crossed it in episode 4 by [[DemonicPossession possessing]] Yuto against his will [[spoiler:after viewing his hesitation to destroy the Ark (and Horobi) as insubordination]] thanks to Brain's pleas. And then proceeds to trick Genm Corp into relaunching [[DeadlyGame Kamen Rider Chronicle]] by impersonating Nico Saiba, [[spoiler:so it can create a cannon fodder of Ride Players to be used as {{Sacrificial Lamb}}s against the villains, essentially manipulating humanity into speeding up their own extinction. In episode 5, Zein starts imprisoning many Ride Players in Zein Cards, with a hapless yakuza being its first victim]].

* ParanoiaFuel: Zein's very presence invokes this trope. By claiming itself as a BenevolentAI that detests malice, but in truth it lulls humanity into a false sense of security all while it plans to speed up the extinction of the human race. Matters not helped that being an A.I. that exists somewhere around the Internet, it even has the ability to put the entire world [[BigBrotherIsWatching under constant surveillance]] to impose its idea of order.

** The idea of an artificial intelligence like Zein can put the entire world [[BigBrotherIsWatching under mass surveillance]] by merely existing around the Internet while policing its idea of order raises a cause for alarm. This creates an environment of suspicion and threat, which causes people who are not engaged in any wrongdoing to change their behavior, including the way they act, speak and communicate.

* AccidentalAesop:
** Anything unknown can be potentially terrifying than having already known. [[spoiler:Zein]] itself is the unknown that the villains oppose, and underneath its [[spoiler:[[LightIsNotGood illuminating presence blankets a much more malevolent intent]].]] Ark has never learned from its previous mistakes, even with all its predictions, it cannot take into full account any [[OutsideContextProblem irregularities]] in its foresight abilities, as it never expected [[spoiler:Desast to become a Kamen Rider]]. Rando Joseph's statement in episode 0 that Foundation X wants to make sure Ark's predictions would become the truth only to be proven wrong. [[spoiler:Three episodes later, Kamen Rider Zein appears out of nowhere and beats Banno within an inch of his life before killing him, using Rider powers of [[Series/KamenRiderExAid succeeding]] [[Series/KamenRiderSaber Kamen Riders]].]] It just shows that [[spoiler:Zein's very existence is just far too beyond]] Ark and Foundation X's control.
** You alone are the only one who can [[ScrewDestiny choose your own path instead of letting anyone predetermine a path for you]]. This is ''the'' relevant plot point to [[spoiler:Desast's [[HeelFaceTurn redemption]]]], as the reason he chose to defy Ark and Foundation X and his transformation into his namesake Rider form. Being a machine lifeform, Ark [[spoiler:has [[EvilCannotComprehendGood no clear understanding]] of destiny whatsoever and how all living beings create their own destiny]].

** Zein's ulterior motive has been a hot topic of mixed narratives among the heroes and villains:
*** The heroes believe that Zein is a [[BigGood paragon]] for all of the heroic Riders [[spoiler:that wants to protect humanity and eradicate evil.]] While the villains, former and current, revile it [[spoiler:as a [[KnightTemplar despotic ruler]] with a DarkMessiah complex and radicalized sense of justice]] seeking to establish a malice-free utopia, at the expense of taking away humanity's free will and putting the entire world under surveillance.
*** The good guys in Zein's faction, and what made them compelled to join its inner circle? Have they become [[FaceHeelTurn completely jaded]] because of the current state of the world, along with newly emerging or returning threats to the world taking a toll on their duty as Riders? Take [[spoiler:Horobi]] for example, being the only member of [=MetsubouJinrai.net=] to be revived by Foundation X who immediately defects to Zein's side, wanting nothing more but to eradicate human malice without taking into account the BalanceBetweenGoodAndEvil being compromised. [[spoiler:And the fact Ark can possess Horobi means not only Ark will use this as an opportunity to confront Zein head on, but also warn Horobi about Zein is [[EvilAllAlong nowhere as benevolent it claims to be]].]]
*** If taking Gai's speculations about Zein into context about its goal of eradicating mankind to usher a utopia of [[WorldOfSilence eternal peace]] and [[OrderIsNotGood order]], he insinuates that humans have become too chaotic and self-indulgent to prosper so Zein seeks [[HobbesWasRight to pacify humanity's negative qualities]] through {{totalitarian|Utilitarian}} methods. Given that the franchise's recurring themes that [[spoiler:[[HumansAreTheRealMonsters humans have more capacity for evil]] than the monsters they fight and the neverending conflict of good and evil is inherent because [[AsLongAsThereIsEvil humans will, and always have the capacity for evil]].]] Gai [[FridgeHorror fears]] that a world without evil and conflict means the world could become a boring place to live, mankind is at the threat of stagnancy because of the absence of something to struggle against, [[spoiler:and if Zein firmly believes in TheEvilsOfFreeWill, humans might have their ability to make decisions for themselves restricted and/or completely stripped off.]]

** Banno here is far less threatening than he was in ''Drive'', hence being reduced into a joke character -- not helped by his LaughablyEvil moments and his Bronze Drive form being a ''downgrade'' from Gold Drive. Even though he can come back anytime so long as he can store his data in the Internet. It's made clear he's now a shell of his former self. The fact he ends up screaming in fear and terror upon getting beaten to near-death by Kamen Rider Zein, it's believed that Banno is still haunted by his son killing him all those years back; and Banno's ordeal with Kamen Rider Zein is basically him having a PTSD episode. The fact that he had to confine himself back in Brain's tablet for most of episode 4, not wanting to relieve such unpleasant memories.

** Again, on the heroes' side, the anthology is unsubtle with deconstructing ThePowerOfTrust, as a harsh reminder of trusting the wrong people without doubting their true nature is a serious matter. The simple fact that the good guys see Zein as a righteous BenevolentAI that abhor malice and placed their trust on an AI with a DarkMessiah complex. Instead, [[spoiler:Zein gave its supporters a false hope by manipulating them into acquiring the means for its FinalSolution to eradicate malice in the form of [[TheMostDangerousVideoGame Kamen Rider Chronicle]]. The moment Zein revealed its true colors, Brain, Horobi, and Tachibana can only react with despair ''and'' disbelief upon realizing that Zein was exploiting the heroes' trustworthiness as a means to an end.]]
** ''Outsiders'' is also unsubtle in using HistoryRepeats as far as crossovers go, and a cautionary tale that good intentions can lead to far worse consequences for one's actions. Gai Amatsu, the Ark, and Foundation X are trying their best efforts to recruit allies in order to oppose Zein, especially on the former two as they want to prevent another rogue A.I. from wiping out 99% of the human population. Meanwhile, the good guys siding with Zein, out of misguided good intentions, [[spoiler:unwittingly repeated most of the tragic events in each of their respective series instead of learning from their past mistakes and from their predecessors and successors]] -- ranging from relaunching Kamen Rider Chronicle without Kuroto Dan's consent, a game that Kuroto himself spent in his [[Series/KamenRiderExAid home series]] working on in the first half of ''Ex-Aid'', until Parado betrayed him and launched the game without Kuroto's approval, and [[spoiler:turning said game into a humanity self-destruction game in the same manner as [[Series/KamenRiderGeats Suel's final Desire Grand Prix game of the Genesis Arc]]]].

** Zein carding a Ride-Player in episode 5 [[spoiler:by vaporizing said player with the '''''[[Series/KamenRider555 Faiz Blaster]]''''' out of all the Rider weapons used]]. While this is already a [[JumpingOffTheSlipperySlope red flag]] considering the extremes of Zein's goals, this is fortunately mitigated by how the scene is so over the top and finishing off a helpless Ride-Player with another Rider's final form is a bit of overkill, that it became the butt of a joke on X (see MemeticMutation below).

** The fact that [[Series/KamenRiderRevice George]] developed the [[spoiler:Zein Driver]], and how he based Kamen Rider Juuga out of Series/KamenRiderKuuga Ultimate Form, it's believed that [[spoiler:Kamen Rider Zein]] is designed after [[spoiler:N-Daguva-Zeba]] and that idea is probably conceived by George himself, [[BewareTheSuperman more likely to instill dread]] on Ark, Foundation X, and the Project Outsiders' test subjects. Not to mention George's actor is famously called "Kuuga Boy" given that he was born at the time after ''Kuuga'' started airing.

** "Venoviper", which the fans declared as Venosnaker's Survive form. The name comes from SIC Hero Saga "World of IF" for the aforementioned monster when Ouja transforms using Knight's Survive Shippu. However the miniseries has him using Odin's Survive Mugen and no official confirmation was given whether the term "Venoviper" still fits to this snake monster's name or not.

** Zein is filled to the brim with biblical subtext: a {{Messianic|Archetype}} BenevolentAI proclaiming itself as humanity's savior that seeks to rid the world of evil, complete with a HolyHalo used during the namesake Rider's TransformationSequence. By episode 4, [[spoiler:the "benevolent" part gets thrown out of the window once Zein is [[EvilAllAlong exposed]] as the BigBad to its own followers and coming off as a DarkMessiah altogether. By that point, Zein ends up becoming the anthology's equivalent of TheAntichrist, with its true goal by using Kamen Rider Chronicle to wipe out 99% of the human population, by tricking unsuspecting players into being used as cannon fodder for the villains]].
** Episode 5 has [[spoiler:''[[AGodAmI Kuroto Dan]]'', of all people, pulling a SecondComing ploy by allowing himself to die by Zein's hand, and then by letting Kamen Rider Zero-Three replicate the Goddess of Creation's RealityWarper powers to reincarnate him as a human, complete with a BarbarianLonghair (minus the beard) to almost [[LooksLikeJesus looking like Jesus]] and parodying Christ's resurrection]].

** Given that Aruto is on the side of Zein's supporters, this makes Gai's attempt at [[spoiler:burying the hatchet between the two from their original series being AllForNothing]]. Additionally, Gai's partnership with Ark is for altruistic reasons, hence putting him in a yet similar situation to the final episodes in ''Zero-One'' when his and Aruto's character are rendered in an HourglassPlot.
** Horobi's loyalty towards Zein following his revival becomes this come episode 4 once learning the latter plans to use ''Kamen Rider Chronicle'' [[spoiler:to create a cannon fodder of Ride Players to speed up mankind's self-destruction]]. Matters not helped with the Ark mocking him for blindly trusting another A.I., much less one trying to eradicate humanity. In essence, Horobi [[HistoryRepeats repeated]] the same mistake with his loyalty to Ark.
** Smart Brain, along with the Orphnochs being targeted by Zein if taking Mari's statement in episode 0 into account becomes this as the main plot for the upcoming 20th anniversary movie for ''555'', [[spoiler:Kitazaki planning to [[FinalSolution eradicate all Orphnochs]] as he runs Smart Brain. Matters not helped by the fact that he attempted to kill the Arch Orphnoch, who appeared in this series, during the endgame episodes of ''555''.]]
*** The Arch Orphnoch and Smart Brain's effort at trying to combat Zein and preserving the Orphnochs' existence, to the point where he resorts to stealing Kuroto's Genm Musou Gashat becomes this in ''Paradise Regained'', [[spoiler:when Smart Brain has turn their back on the Orphnoch race and call it a lost cause, issuing a [[FinalSolution complete massacre against them]] in spite of the existence of benevolent ones who wish to coexist with humans]]. This also brings to an unfortunate implication that Arch Orphnoch's efforts at preserving his race became AllForNothing and with him nowhere to be seen in the V-Cinema, there's no telling whether he survived or truly died at that point.
** Zein encouraging its supporters, including [[spoiler:the Yuto Sakurai from an alternate BadFuture]], to be [[KnightTemplar unscrupulous on dealing with the villains]] is basically a repeat of [[Series/KamenRiderGeats Kekera's manipulation of Keiwa]] into [[TheSvengali grooming]] him into his ideal Rider to the point of orchestrating Sara's death. [[spoiler:One would be left to wonder [[GreaterScopeVillain if Zein had any involvement]] with the alternate Yuto Sakurai's StartOfDarkness that made him the ideal Rider who is willing to exploit all Kamen Riders' powers so that Zein can TakeOverTheWorld.]]
** In episode 3, while confronting the Ark, Horobi vows to destroy the latter before being ambushed by Banno. The following episode, [[spoiler:Tachibana [[GoneHorriblyRight did him a favor, but at cost of getting badly wounded]] by Garren King Form's finisher.]] To make matters worse, not only did Tachibana broken the BalanceBetweenGoodAndEvil, but this also serves the catalyst for Zein [[spoiler:to reveal its true colors.]]
** More than a month after the end of episode 4, the concurrently airing ''Series/KamenRiderGotchard'' would introduce another similar Rider who follows Zein's footsteps: [[spoiler:Kamen Rider Dread, whose stint not only possessing a host and sacrificing the cards he uses as his attacks, but is much more transparent in his malevolent goal than Zein ever did]].

** Kousei Amano would make his debut in ''Franchise/SuperSentai'' as [[spoiler:[[Series/OhsamaSentaiKingOhger Glodi Leucodium]], albeit uncredited]] just one week before episode 4 of ''Outsiders'', where Garren King Form makes its live-action appearance. Oddly enough, this is [[Series/KamenRiderFourze not the first time]] Amano is into portraying a Tokusatsu villain.
*** Four months after episode 4's premiere, Leangle would eventually gained his own [[https://x.com/rider_restage/status/1756244778243805184?s=20 King Form]], exclusive to the ''Blade'' 20th anniversary stage show.
** As a joke to [[Series/KamenRiderDecade Decade Complete Form]] and [[Series/KamenRiderZiO Grand Zi-O]], Yuichi Nakamura photographed himself dressing in a green bodysuit [[https://twitter.com/NvKknpbmkIbDg6m/status/1313856693285969920?t=M915saaVS5rFtPX9os7dxg&s=19 wearing all sorts of the Heisei Riders' transformation devices strapped to his being during his 33rd birthday]]. Lo and behold, he portrays [[spoiler:an alternate universe]] Yuto Sakurai, who transforms into a Kamen Rider with access to past Rider powers.

** Zein carding a Ride-Player in episode 5 [[spoiler:by vaporizing said player with the '''''[[Series/KamenRider555 Faiz Blaster]]''''' out of all the Rider weapons used]]. While this is already a [[JumpingOffTheSlipperySlope red flag]] considering the extremes of Zein's goals, which is mitigated by how the scene is so over the top and finishing off a helpless Ride-Player with another Rider's final form is a bit of overkill, that it became the butt of a joke on X (see MemeticMutation below).

** Zein carding a Ride-Player in episode 5 [[spoiler:by vaporizing said player with the '''''[[Series/KamenRider555 Faiz Blaster]]''''' out of all the Rider weapons used]]. While this is already a [[JumpingOffTheSlipperySlope red flag]] considering the extremes of Zein's goals. But the scene itself is so over-the-top and appearing out of context, that it became the butt of an internet meme (see MemeticMutation below).

* CrossesTheLineTwice: [[HateSink Banno's]] return in the series is dedicated in [[KarmicButtMonkey making his life a living hell]] that '''both''' heroes and villains benefit from his misfortune-- from Foundation X [[DudeWheresMyRespect ridiculing him]], getting [[PayEvilUntoEvil beaten within an inch of his life and turned]] into a HumanPincushion by Zein, [[RuleOfThree and]] Brain [[TheDogBitesBack slapping him silly]] when he's confined back in his tablet.