Hate Sink / Kamen Rider

Shinnosuke Tomari: You Bastard! Don't you have any pride as an officer?
Mitsuhide Nira: You're just like your father! An officer's pride? Please... Not even a hint of it! Too bad for you!

—Kamen Rider Drive

The Kamen Rider series has a diverse number of characters over the course of its run - heroes, allies and villains alike, and more often than not you're more likely to be in awe of them. The villains in particular, regardless how heinous they are, at least they have some aspects of their character that makes them fun or enjoyable to watch, such as Kuroto Dan's hamminess or Blood Stalk's Trollish charm. The same cannot be said with these characters, as you can detest them at your heart's content.

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Heisei Era Phase 1

• Kamen Rider Kuuga: Go·Jalaji·Da stands out as one of the worst Gurongi in the series without any humanizing qualities, even in a blood-thirsty tribe that kills humans for game. He inflicts one of the crueliest killing methods in the series on his victims, by using his needles to cause them to develop fatal encephalitis, or inflammation of the brain. Even worse, he specifically targets second-year high-schoolers, no older than 14 years old, enjoying the scene to see his victims suffer and showing no remorse over his crimes, which pushed Godai into a murderous rage. Even when a victim questioned his motives, all Jalaji answered was how he enjoyed seeing his victims afraid of him. Needless to say, Jalaji's painful beatdown and death at Kuuga's hand is more than well-deserving for him.
• Kamen Rider Ryuki:
  • Takeshi Asakura/Kamen Rider Ouja is a violent, bad-tempered, murderous, and sadistic man who finds joy in fighting, maiming, killing, or otherwise destroying anything in his random fits of rage. He has no sympathy or remorse for his actions and will attack anyone simply because he is "vexed", to the point he would even go as far as to hurt himself, just to ease his tension. Unlike the other Riders who join the Rider Fight in order to have their wishes fulfilled (even if some of them are selfish), Asakura is simply having fun with killing and fighting. In fact, if he won the Rider Fight, he only states his wish is to make the Rider Fight endless, so that he can continue his destructive routine more and more to feed his urge for violence. Unfortunately, his character is popular enough to create his archetype for more villains in the following seasons.
  • While he's not on the same levels as Asakura, Jun Shibaura/Kamen Rider Gai also qualifies. He is a self-centered and arrogant man who takes pleasure in boasting his superiority and loves toying with other people's lives for nothing more than to satiate his sick sense of humor. He also prides himself on his resourcefulness and intelligence, which allows him to be able to manipulate other people the way he sees fit. However, this trait became his primary Fatal Flaw, as he arrogantly (and wrongly) thinks that his intelligence will enable him to control the Asakura as mentioned above - one of the most dangerous and the most loathsome participants of the Rider War, only to be manipulated himself in the end.
• Kamen Rider 555:
  • Even by Secondary Riders' standards, Masato Kusaka/Kamen Rider Kaixa could be the most loathsome Secondaries of all time. On paper, Kusaka is calm and polite towards everyone, except for Takumi Inui/Kamen Rider Faiz, but Takumi himself can see that he is a selfish, vindictive, and skilled manipulator who has no qualms about driving a wedge between Takumi and those around him like Yuji Kiba/Horse Orphnoch so he can have Mari Sonoda for himself. Unlike most Secondary Riders who start off hostile towards the Main Riders and become the Main Riders' allies later on, Kusaka continues to remain a nasty, cold-hearted, and spiteful person who refuses to befriend Takumi. While his Freudian Excuse is understandable, and Takumi tried his best to help him for the better, Kusaka continuously treats him like crap. Even in his final moments, Kusaka is still arrogant and sociopathic with almost no redeeming qualities, with his death at Kiba's hands being very much deserved.
  • Kitazaki/Dragon Orphnoch, the youngest member of Lucky Clover and the most ruthless Orphnoch to work for Smart Brain, is very arrogant and self-absorbed, often referring to himself as the 'strongest lifeform' due to his abilities. These talents also made Kitazaki withdraw from society and have a childish outlook on the suffering of others as fun.
  • Masahiko Minami is an extremely xenophobic madman who believes that "monsters" deserve to be experimented on for not being human, and despising those who are pro-Orphnoch. He even spends his last few moments laughing in Kiba's face as he is dying and gloating that the Orphnochs will never succeed.
• Kamen Rider Blade:
  • Isaka/Peacock Undead, the first of the Royal Clubs, acts like an unempathetic Mad Scientist who performs experiments to meet his goals. He first has his men capture Kazuma Kenzaki/Kamen Rider Blade as part of his experiment to test his strength, even making Hajime Aikawa/Kamen Rider Chalice join in with him lest the Kuriharas end up harmed by a bomb one of his men put in the cafe. He eventually made an offer to Sakuya Tachibana/Kamen Rider Garren to get soaked in a tub of Schuld Kestner seaweed under the pretense of eliminating his subconscious fear, the Rider unaware that doing so gave Isaka a mental leash on him. Isaka's ultimate goal was to make his ultimate Rider, Leangle, which involves capturing teenage boys and getting them corrupted by an improperly sealed Spider Undead that he rigged himself. When Tachibana's girlfriend Sayoko found out about the seaweed and tried to help him as best as she could, Isaka eventually offed her for disregarding her warning, which ultimately culminated in getting sealed by Garren for doing so. Regardless, Isaka's actions end up getting Mutsuki corrupted by Spider, which the heroes try to help set their ally free for the rest of the series, even at the cost of having two potential allies to their cause having to get themselves sealed to free him.
  • King/Caucasus Undead acts like an overtly mischievous teenager who enjoys ruining others around him by either slandering with his cell phone or just causing messes in general. King causes the ire of the heroes by performing Fake Tears on Shiori before endangering her with Kotaro, pausing time on Kenzaki via Scarab Undead so he can either escape or fight back, and kidnapping Hajime and making him reveal his Joker form to him if he didn't want the Kuriharas to know his true nature. By doing that third act, King also confiscates the Rouse Cards Hajime had with him at the time, making the Rider slowly lose himself as goes into being the berserk Joker. Despite his claims of being "pacifistic" and having "saved" Nozomi from three men harassing her, Kenzaki points out that King treats things all as a game and has no remorse for whatever he did to his victims.
• Kamen Rider Kabuto: Masato Mishima, Riku Kagami's Evil Chancellor in ZECT, is a heartless man who desires power and attempts to make his superior disregard human life. For a given middle chunk of the series, Mishima had Shun Kageyama under his wing and, in addition to ordering him to go after Gon as leverage against Daisuke Kazama/Kamen Rider Drake, thinks of him as an eyesore because he can only complain and has lost the TheBee Zecter. Not only does he discard Kageyama, leading to the latter's Start of Darkness, but Mishima tries to have the Hyper Zecter destroyed in an attempt to spite Tendou and get the latter assassinated by Renge. Eventually, it turns out that he held Dark Kabuto hostage for years as part of unethical experimentation. By the near end, he and Negishi overthrow Riku as ZECT superiors, attempting to get the populace to put on bracelets that may result in them being Natives, and then aggressively telling Kagami that he always hated honest people like him when the Rider tried to stop their scheme.
• Kamen Rider Kiva:
  • King/Bat Fangire acts as an absolute dictator in 1986 and as an abusive husband to his wife Maya. For the most part, King claimed to Maya that he could not feel love for her because he felt that it was pointless for him, yet after seeing her care for Otoya Kurenai more than him, King then had the violinist kidnapped and even threatened the infant Taiga's line on the life. As Otoya was saved, King ended up stripping Maya of her Fangire powers, claiming it to be a Fate Worse than Death for her and as a sign that he had a tiny bit of fondness for her. By the time of his ultimate defeat by the Kurenais, King attempted to take his wife and child down with him with a blast, claiming that they belonged to him only, before infant Taiga shielded himself and his mother to deflect the blast back to King. Realizing this, King spends his last moments claiming that Taiga was now a newborn king who would be the end of them before shattering to his first death.
  • Dr. Kanda from episodes 34 and 35 is a Mad Scientist and a former member of the Wonderful Blue Sky Organization who performs unethical experimentation on his test subjects. He had Kaede/Horsefly Fangire imprisoned in a cell so that when he was ready for her, he had her trapped against her will when he forcefully transferred Life Energy to her via extremely painful Electric Torture, all this with his desire to make her a powerful Fangire that he establishes. If she defies him, Kanda would still electrocute Kaede anyway. Despite Mamoru Shima's warnings to him to stop using the Fangire for his experiments, Kanda disregards him and continues electrocuting her. After being shocked and overtly mistreated by him too much, Kaede eventually broke free from his control, claiming to Kanda that she was just using him to make herself more powerful before assassinating him.

Heisei Era Phase 2

• Kamen Rider Double:
  • Motoko Saeki, a fellow Wind Wave DJ, out of jealousy that Wakana Sonozaki's show was more popular than hers, manipulated the latter's manager Ageo into being the Violence Dopant even if it could potentially cause countless deaths, even spooking the guy who sold her the Violence Memory. As Wakana found out and was prepared to kill Motoko, her memories of her younger brother caused her to spare her instead. As thanks, Motoko, now having dirt on Wakana, prepared herself in an attempt to expose the latter as a Dopant, only for Kirihiko to arrive and assassinate her to both keep the Sonozaki family safe and out of what she did to Wakana.
  • Hiroshi Sagami/Commander Dopant, is a police captain whose wife was murdered on their second wedding anniversary by a criminal he previously arrested. Unfortunately, instead of simply seeking to arrest him, Sagami became deeply embittered and came to believe that all criminals are unrepentant and the only way to redeem them is through death. As such, he began aggressively hunting down criminals and executing them on the spot with no remorse, even for minor offenses. Not only is he uncompromising and unforgiving, Sagami looks down on the law as being too soft and will do anything to force his opinion onto others, even killing fellow policemen in the name of that goal. When his attempt to force Ryu Terui/Kamen Rider Accel to his ideals failed, he was appropriately fired from his post and arrested for his crimes, being a prime example of what Ryu could've become if he didn't get over his drive for revenge.
  • Doctor Prospect/Eyes Dopant is a Mad Scientist who created Quarks, psychic-powered soldiers created to serve as his own personal army. A personal nemesis to Katsumi Daido/Kamen Rider Eternal, Prospect is cruel and sadistic and doesn't tolerate weakness or disloyalty in his soldiers. Not only does he leave the weaker Quarks to die, but those who complete his cycle of Training from Hell are branded by his dopant powers to die if they ever revolt. Laughing in Daido's face as he killed the quarks to spite him, Prospect's death at the hands of a UNGODLY-PISSED ETERNAL was very well-deserved, though not before his mass slaughter drove the Rider to insanity and made him the monster he was in the present day.
• Kamen Rider Fourze: Hiroki Makise/Pyxis Zodiarts is a creepy to borderline sociopathic Stalker with a Crush who fantasizes about getting along with Yuki Jojima, only tried to kill her once it became clear that she's not going to reciprocate his "feelings" and takes sheer delight in turning girls into "shooting stars" by sending them to an unfinished bridge with a bus. Oh, and he even went as far as to destroy the locker that leads to the Rabbit Hatch, purposefully making it so that Kengo is trapped on the Moon just to spite Yuki (before it was revealed that a Brick Joke from earlier made it so that Makise accidentally took the wrong locker). It is really saying something when he becomes the first Switcher to miss out on Gentaro's friendship offer, leaving him instead to try to flee (in vain) from the girls whom he trapped on the bus. When he returns in the Aquarius Zodiarts two-parter arc and Erin Suda asks Tomoko who he is, Tomoko just answers, "To put it simply, he's a misogynist."
• Kamen Rider Wizard: Sora Takigawa, the Gremlin Phantom, stands out as one of the worst of the Chief Phantoms. While Medusa has a profound sense of loyalty to Wiseman and will do anything to appease him, not knowing that he also played her, and her Gate's sister Mayu like fools, Phoenix has to be kept in line to prevent needless bloodshed, and Fueki himself having orchestrated the show's events all to save Koyomi. Sora was already a psychopath devoid of any redeeming quality, considering that he is a misogynistic Serial Killer who targets women with long, black hair; and it's implied that he's more willing to do the same to Medusa. This comes to a head in the show's end game when he not only murders Fueki but also Koyomi to take the Philosopher's Stone for himself and just to spite Haruto. Once defeated, Sora mocks Haruto for robbing the hope of another person, or in the former's case, his hopes of becoming human again, only for Haruto to rebuke Sora that he already lost his humanity ever since the day he became a Phantom.
• Kamen Rider Gaim:
  • Lock Dealer Sid/Kamen Rider Sigurd is one of Takatora Kureshima/Kamen Rider Zangetsu's employers who takes great pride in smacking around those weaker than him in his Rider form. When enraged or annoyed in a fight, he tends to not hold back on his strength for payback, not caring if he could potentially kill the one he's fighting. He also takes great delight in messing with people's heads and shows no empathy to anyone but himself. It is no secret that Kouta Kazuraba/Kamen Rider Gaim openly hates him, telling the audience to pour their hate onto this sleazebag.
  • Ryoma Sengoku/Kamen Rider Duke is far worse than Sid (mostly because the latter was already killed just before he could prove otherwise). He is a Mad Scientist who uses people as test subjects and cares about his inventions and wants people to show respect and trust in them. His overall actions have made him almost put the world into utter destruction due to his experiments and his ambitions of grasping the Forbidden Fruit.
  • Demushu is a vicious warmongering Blood Knight Overlord Inves who desires to imperil others he deems weaker than him and can easily be vexed at what he considers anything to be an insult to him. After noticing a Crack to Earth, Demushu takes no chances and heads there to cause endless mayhem in that dimension. Even after Kouta spent a few episodes attempting to reason with him, once Demushu makes it clear to him that freely admits he enjoys hurting people for the sake of hurting them, the Rider ultimately stops trying to appeal to the Overlords in general and eventually decides to fight him very seriously.
  • Redyue is another malevolent Overlord, wanting a 'toy' to alleviate the boredom of existing in Helheim for so long, and is plain manipulative in general. After invading Earth with an abundant amount of Helheim vines and Inves, Redyue then decided to have other countries wage war against Japan as part of her demented amusement. Her plan for having the Overlord Queen resurrected involved capturing numerous civilians and placing them on her machine to transfer energy for the revival. Redyue later reveals to Kouta that she enjoys having her toys break, which she hoped for what happens to Mitsuzane despite partnering with him, then eventually performing Mind Rape on him in an attempt to give up his humanity and join the Inves side. Once Rosyuo acknowledged Kouta's strength, Redyue unhesitatingly backstabs him in an attempt to get the Forbidden Fruit from him to rule whatever she saw fit. Yet once what she got is rotten, she angrily beats up Rosyuo, demanding the Fruit from him, and once she murders him, Kouta becomes angered enough to ultimately finish her off.
  • Shura from Gaim Gaiden: Kamen Rider Knuckle was a former member of a dance team in what would become Team Baron. When Kaito Kumon takes over the team, Shura attempts to attack him from behind out of spite, he quickly kicks him out as punishment for his cowardice. Establishing Neo Baron, as an underground fight club, with ties to a cult known as Black Bodhi. Shura embodies Kaito's Social Darwinist worldview to an extreme, lacking the latter's honor and moral compass; to the point that he has no hesitation of fighting dirty when things turn south for him. Zack even points out that his cowardice is his only weakness for all his bluster and sees Shura's transformation into Black Baron as nothing more but a mockery of Kaito's legacy.
• Kamen Rider Drive:
  • Tenjuro Banno/Gold Drive is a cruel, sadistic man whose constant failures to advance or complete his Roidmude research drove him to insanity. He was also petty as during one of his experiments on one of his Roidmude creations, Heart, he made his human form based on a billionaire who refused to invest in his research to enact his fantasies of torturing him. He also displayed narcissistic tendencies, as he believed anyone who did not understand his supposed genius was beneath him and enjoyed making those kinds of people suffer. He also never viewed the members of his family as anything more than research subjects. When the table turned in the Final Battle and he's begging his son Go Shijima/Kamen Rider Mach to not destroy him after being defeated, it's not hard to see why his final death by his own son is much deserved.
  • Mitsuhide Nira/Thief Roidmude, the manager of the First Investigation Division of the Tokyo MPD, is an irritatingly obnoxious bully to the Special Investigations Unit, constantly taunting them and acting like a spoiled brat as he lectures anyone he sees as inferior. To top it off, he is the one responsible for killing Eisuke Tomari, Shinnosuke/Drive's father out of pettiness and jealousy. Even after the truth comes to light, he doesn't even repent after getting arrested, yelling that the fight is far from over and hoping for Shinnosuke and the rest of the Special Investigations Unit to be destroyed.
• Kamen Rider Ex-Aid: Masamune Dan/Kamen Rider Cronus is much worse than his son Kuroto/Genm. He is a manipulative and remorseless Control Freak with a severe god complex who has no qualms about murdering others and committing underhanded tactics to get what he wants. Once he starts tasting his first defeat by Ex-Aid Hyper Muteki Gamer, Masamune becomes more prone to violent outbursts to the point of being paranoid, which is well deserved. Even after being defeated for the final time, Masamune rejects Emu's offer to turn himself in, and kills himself by stabbing the Rider Chronicle Gashat into his chest in an act of spite, not only rendering the Doctor Riders' efforts to bring back those who died in the Bugster infection moot, it shows that not only he is not much different than his son was, he considers himself to be the only one deserving to pass judgment, and that no one else has the right to do so onto him.
• Kamen Rider Build: Juzaburo Namba is a war profiteer who collaborates with Faust to instigate a war between the three warring nations to see which of them are determined enough to unify Japan. He also abducted children, with years of training and indoctrinating them into Namba Children, a group of loyal lapdogs working for his causes. He is also a Dirty Coward who just uses others with no care, making sure his pawns fight until death while he himself stays in a secure place. When Evolt comes to kill him for attempting a double-cross, Namba falls out of his chair and spends his last moments on the floor fruitlessly trying to bargain for his own life.
• Kamen Rider Zi-O:
  • While most of Time Jackers are no saints, Swartz/Another Decade is perhaps the worst of them. He is also very arrogant and does not leave room for anyone "lower than him" to express their opinion. Initially, he appears to be solely motivated by creating the new King replacing Ohma Zi-O in the future by creating Another Riders by force, but any Another Rider hosts are nothing but mere guinea pigs to him, and even Heure is no exception. As the series progresses, Swartz's actions make it more and more evident that he is secretly preparing for a personal agenda: to be the new king by reclaiming the throne he has been denied from his royal family by amassing as much power as possible via merging the Riders' worlds together.
  • Asura/Another Gaim, after being kicked out of Team Baron by Kaito Kumon and becoming Another Rider, sends any who question him or get in his way to an artificial version of the eldritch Helheim Forest, isolating them for five years until they are finally released. He ultimately stands out as one of the worst Another Riders compared to his predecessors and successors. Even the likes of King Kuroto Dan, Hiryu Kakogawa, and Yuko Kitajima have some more redeeming (or at least entertaining) qualities by comparison.

Reiwa Era

• Kamen Rider Zero-One:
  • Gai Amatsu/Kamen Rider Thouser is perhaps one of the most despised antagonists of the Kamen Rider series in modern era. He's the one truly responsible for the destruction of Daybreak Town via corrupting the Ark to believe Kill All Humans leading to the rise of MetsubouJinrai.NET. He later exploits this to frame all HumaGears as killing machines in order to sink Hiden Intelligence's stocks so he could acquire the company. Even when he's not being an outright villain, Gai is still an utter Jerkass to everyone around him. He takes every available opportunity he can to demean and put down Aruto Hiden/Kamen Rider Zero-One, forces ZetsumeRisers onto HumaGears to turn them into Magia just so he can destroy them to spite Aruto, constantly cheats and uses underhanded tactics while accusing his opponents of doing it instead, preaches a Humanity Is Superior philosophy at the same time he is sacrificing and endangering human lives for his goals, and even treats his own subordinates like trash, using Mind Control chips implanted in their brains to force them in line and openly referring to them as being just tools. His relationship with his right-hand woman Yua Yaiba even has some echoes of Domestic Abuse, with her remaining submissive to him even as he verbally abuses her (likely due to the chip in her head). Every episode sees Gai finding a new way to Kick the Dog. Despite this, Gai has an unnatural charisma about him and an ability to time things just right to make it seem like he's the hero, and Aruto, the one actually trying to achieve coexistence between humans and HumaGears is the villain. It's really saying something when his actor, Nachi Sakuragi, stated in interviews that not only does he deliberately makes Gai despicable via his acting, his goal is to make Gai even more hated than Masato Kusaka (from Kamen Rider 555, mentioned above), who is one of if not the single biggest Hate Sink in the entire Kamen Rider franchise (other candidates being outright villains like Takeshi Asakura, Tenjuro Banno, or even As from the same series, again, mentioned above in their respective series). All this makes him a very fun character to root against and makes every time the heroes manage to get one over him much, much sweeter.
  • Masamitsu Yuto, the fifth and final ZAIA representative of the Workplace Competition, is an anti-Humagear politician who is ultimately the meanest of the five. Firmly believing that Humagears cannot coexist with humanity, he resorted to bribing the crowd into voicing for him and denied Check-It-Out's accusations towards him and his men of his crimes in order to turn the once-beloved rapper against the public, thus securing ZAIA's victory in the competition. Ultimately, the only form of punishment he and his associates got was being chased out the scene with the rest of the crowd by Isamu Fuwa/Kamen Rider Vulcan, nothing for his crooked actions.
  • As, Is' Evil Knockoff, despite her jovial nature, is, by far, the worst among the villains in the series. Under her alleged devotion to the Ark, As masterminds a war between humans and Humagears by approaching members of both sides when they're at their lowest point and offering them the power to seek revenge through her False Reassurances. She is also void of concern over her kind's well-being in general, thus reinforcing her sadistic disposition. One recurring mental vision of Aruto shows As embracing him from behind over a field of the Ark's malice, with her creepy smile showing over a menacing angle. Her goal, in fact, is to create hundreds of Arks so that they can destroy each other and everything else. Even after her plan backfired, she managed to set up events for The Movie by bringing S's rise to power with the items for Kamen Rider Eden. After her supposed partner-in-crime Lyon Arkland/Kamen Rider Zaia had one of his Solds headshot her, no tears were shed for As.
• Kamen Rider Saber: Isaac/Kamen Rider Solomon, the current Master Logos, initially appeared to be a wise and calm leader who guided the heroes in the Sword of Logos to protect the world by any means. But behind his wise and calm facade, lies his maniacal nature. Unlike previous holders of the title, he constantly breaks the rules, discarding his duty for his selfish desire, and has a maddening god complex. His crimes are: manipulating Hayato Fukamiya/the first Kamen Rider Calibur 15 years prior into believing that what he was doing was truly going to save the world, sending Reika Shindai/Kamen Rider Sabela to Northern Base to sow discord between the swordsmen, releasing Bahato/the first Kamen Rider Falchion for the second time due to their goals being similar, and allying with Storious to complete the Book of Omnipotence. His megalomania is taken to the extreme once he obtains the Omni Force Wonder Ride Book, becoming Kamen Rider Solomon and proclaiming himself an actual god. Yet at the same time, this was his biggest Fatal Flaw. Once Touma Kamiyama/the second Kamen Rider Saber obtained the Haouken Xross Saber, everything went downhill for him; he got beaten at least thrice, yet he refused to accept defeat and repent, resulting in him being reduced to a sobbing wreck. He spent his last minutes being livid over how things did not proceed in his way before he was quickly killed by Storious when he yelled at the latter to kneel before him. A peak example of The Caligula in the Kamen Rider franchise, Isaac's atrocities ended up changing things in a very different direction than what he intended, complete with the abolishment of the title he so thoroughly disgraced.
• Kamen Rider Revice:
  • Yasushi Kudo is a corrupt lawyer and contract holder of the kangaroo and saber tiger deadmen. Not only are his business practices openly revolting, Kudo, in spite of his sad past, shows little to no redeeming qualities, and sees Ikki's empathetic nature as nothing but pure arrogance. Because of his willingness to harm Ikki's family and cause indiscriminate damage against civilians and innocents, Kudo more than deserved his final fate of being absorbed by Giff.
  • While two of the Deadmans trio have sympathetic traits, this cannot be said with Orteca, who is the most despicable among the initial trio. Despite having a tragic backstory and therefore something to sympathize with him for, Orteca's heart is blacker than squid ink, and he'll not only sacrifice his colleagues and followers as cannon fodder but will ruthlessly cut down others simply for kicks and to spite the heroes. Completely unapologetic about causing others misery for his own selfish end, Orteca is the most despicable man the Riders have ever dealt with by far.
  • The Kamen Rider Vail miniseries gives us NOAH director Agriyama, who saw the titular Rider as nothing more than a tool and even ordered Vail to execute his parents for their own ends. With his personality showing the most despicable lows a Rider Character can reach, Agriyama is so twisted that a good number of his men turn their backs on him after Vail runs amok, and his death at Vail's hand is well and truly deserved.
• Kamen Rider Geats: Where do we even begin?
  • Kanato Sumida/Kamen Rider Da·Paan shows that while most Desire Grand Prix participants with a Dark and Troubled Past are shown to be very approachable or a Jerk with a Heart of Gold at the very least (emphasis on "most"), the same absolutely can NOT be said about certain participants like him. An aspiring basketball star who was forced to quit his pursuit after a Career-Ending Injury, Kanato became embittered at not just those who glossed over him, but all of humanity, so much so that the extinction of his own race was his wish for the Desire Grand Prix. As if that wasn't enough, he willingly and openly attacked other Riders purely out of spite, despite the rules of the DGP forbidding such an act. This ultimately gets him eliminated, and he vanishes after a Villainous Breakdown-induced Evil Laugh.
  • Morio Koganeya/Kamen Rider Mary puts on a relatively convincing Nice Guy facade at the start, but later he is revealed to have previously been a dealer in an illegal underground casino who embezzled money and escaped arrest, and shows himself to be an unscrupulous jerkass who cares about nobody but himself. Additionally, he is more than willing to sabotage other players to the point of catastrophic and fatal failure. Needless to say, he was far from liked as the mask began to peel off, and upon his elimination, he vowed to get revenge. To say nobody missed him following his retirement would be an understatement, as he was forgotten not long afterward.
  • (Kamen Rider) Beroba, the Jyamato sponsor. Nobody who sponsors the Riders appears to like her, and it is not hard to see why: She's a totally maniacal self-described sadist who revels in causing misery, loves to torment people, and shows no form of compassion or respect towards anyone but herself. Not only is she incredibly selfish and apathetic, Beroba has no qualms about turning on her allies and utterly destroying everyone in her path so that she can get what she wants... and that's not even mentioning her Evil Laugh. Given that she successfully took over the DGP and essentially gave the Jyamato free reign to MASSACRE EVERYONE IN SIGHT, showing nothing more than nonchalant glee for it all, Beroba's actions make Kanato and Morio look like preschool bullies by sheer comparison. She cements herself as one of the worst characters in the entire series with her acts of sadism against Neon in #29 sending Ace completely apeshit, and seeing her get defeated as Glare2 by Geats LaserBoost form never fails to leave a smile of content. Considering how utterly petty she turns out to be, her defeat by Na-Go's hands is very satisfying, topped only by the fact she met her end by Buffa, the same Rider she supported.
  • While Daichi Isuzu/Kamen Rider Nadge-Sparrow is relatively tame compared to Beroba, he still qualifies due to matching both Kanato and Morio. To put it simply, this guy will not hesitate to perform acts of cruelty without any form of remorse in order to accomplish his goals, and he couldn't care less about anybody else. This makes seeing him get his just desserts all the sweeter, particularly due to the fact he was Hoist by His Own Petard both times. Unfortunately, he is annoyingly persistent, which means that as shown by his planning of Sara's death he only has more time to grow worse. By the time he fully indulges in his newfound role, Daichi has become so despicable that not even the villains are willing to save him in spite of his significant part in their plans.
  • While it's not as prominent in his earlier appearances, later episodes make it clear that there is absolutely nothing likable about (Kamen Rider) Kekera. With a sense of apathy that gives Beroba a run for her money, Kekera does not care to any degree about Keiwa's well-being and sees his attempts at heroics as only a source of entertainment. Add the fact that he outright applauds Sara's death instead of mourning it and you have one of the most despicable Rider characters in the entire franchise.
  • The Creation arc would give us the third game master, Zitt. Brutal, efficient, and caring only about giving bad ends, Zitt is Suel's equal in the apathy department, laughing in Keiwa's face when he questions about it.
  • Episode 43 drops two characters with this as their entire thing, Kirito Asari/Kamen Rider Turbon and Kazuo Numabukuro/Kamen Rider Brali. The former is a gang leader who only joined the DGP to use its equipment for mass riots, and in the present day was responsible for killing Keiwa's family a second time. The latter not only revels in killing children, but was the one responsible for the death of Neon's predecessor, which he gleefully rubs in the face of Kousei upon his revival.
  • Despite all of the above, the series' biggest scumbag has to be Suel, the one behind the Desire Grand Prix. Openly dismissing the DGP players as insignificant circus animals and so ridiculously apathetic he makes Beroba look merciful, Suel makes it absolutely clear that he doesn't give a damn about anyone he deals with, as shown by having Samas flat out murder Niram and letting Mitsume die during the Grand End. This makes Ace's epic ass-whupping as Geats IX against him as Gazer all the sweeter, on top of the inherent awesomeness already present in Geats IX. As his true sadistic self shows itself in the final episodes, Suel leaves behind the legacy of a man who is the worst of the worst within the franchise, making his final demise at the hands of the Riders he saw as beneath him the cherry on the sundae.
  • The King Jyamato in Jyamato Awakening. Not only is he willing to murder parents, but he shows no mercy to the more peaceful members of his own species, clearly delighting in causing misery to Ace and Haruki. Unsurprisingly, the other Riders treat him with disgust, and seeing him bite the dust after his vile deeds is just the cake's icing.
• Dear LORD, Kamen Rider Gotchard. Almost every host to the Monster of the Week in each episode is a despicable scumbag, allowing it to eclipse even Geats' record in under half the time.
  • Amongst the worst of them is the Dragonfly Malgam's host, Kenji Sunayama, a businessman with a Hair-Trigger Temper who has a single-track mind to ensure his son does nothing but schoolwork. This wouldn't be so bad if it wasn't for the fact that he'll openly yell at him if he thinks his son is even slightly deviating from his studies, and after becoming a Malgam is not opposed to simply shooting his son with flying projectiles AS PUNISHMENT FOR HAVING FUN. Kenji's bad parenting and willingness to attack his family make him one of the worst of the Malgam hosts in the series, which is a high bar to jump over considering the previous non-general hosts include a stalker and would-be serial killer. Ironically, upon his defeat, he actually shows genuine remorse for his actions, whereas most of the other Malgam hosts are unrepentant.
  • Topping Kenji is Tsurugi Himeno, the first host of the Battery Malgam. Driven insane by having to take care of his sister after their parents died, he turned to crime and committed serial arson before getting locked up. After escaping, his first action after seeing his sister again is to tell her that he plans to MURDER HER. He may have had a Freudian Excuse, but his Freudian Excuse Is No Excuse, as while Kenji was at least somewhat remorseful for his deeds, Tsurugi is completely unapologetic, and this combined with his psychopathic tendencies makes his Laser-Guided Karma much more satisfying than usual.
  • Shiori Hiyama, the second Spider Malgam, is arguably worse than Tsurugi in a number of ways; while she may not have been willing to kill her relatives, Tsurugi was a regular human while Shiori was a high-ranking alchemist. As such, she is far more dangerous even without Malgam powers, and combined with a Social Darwinist mentality alongside a superiority complex you get one of the biggest Hate Sinks in the series.
  • Her boss, Licht Kugumiya, isn't as bad at first, being absolutely dickish to Houtarou at worst, but that all goes out the window once it's revealed that he only became an alchemist just so he could take revenge on Ace, who in a past life managed to defeat him. Utterly uncaring about who or what he has to sacrifice in the name of that goal and completely selfish and apathetic about everyone else, Licht is the utter epitome of Evil Is Petty and far more of a monster than the Chemies ever were.
  • And as if the list wasn't long enough, we have Geryon at the very top. A man who only studies the effects of malice and disregards the lives of everyone, be they, Chemy, human, or even his own subordinates, the villain of the Alchemist society's most famous story earned that spot for a reason; he's so apathetic and sadistic that it's the only label applies to him, which he does little to disprove otherwise.

Spin-Offs

• Kamen Rider Amazons: Takaaki Tenjo is the Social Darwinist figurehead of Nozama Pharmacy who is the primary source of the conflict in the series. In a world of Grey-and-Gray Morality where it is about kill or be killed. Tenjo is just as vile as he can be. He openly shows a disregard for human life to stroke his Darwinistic worldview and it shows how mankind can be just as monstrous than the Amazonz. And what makes him so repulsive is that he gets away without any comeuppance in the end.
• Kamen Rider BLACK SUN:
  • Wataru Igaki is among the worst of humanity's negative traits, holding up various protests and demonstrations against Kaijins, under the belief that they are not human. Perhaps his worst act was brutally beating Shunsuke Komatsu to death alongside other humans without remorse, and then hanging his corpse to make an example from him to show that Kaijins are inferior to humans. To say that his gruesome death at the hands of Nobuhiko Akizuki/Kamen Rider Shadow Moon was well deserved is a massive understatement.
  • Prime Minister Shinichi Dounami is a bigoted, petty, greedy and utterly self-serving scumbag with absolutely zero redeeming qualities of any kind, and he's even incompetent as a politician at that. His brutal death at the end, engineered by his own subordinate, whom he constantly abused, in an act of spite, is very well-deserved.
  • Bilgenia is easily the most barbaric villain in the show. While he may have once genuinely believed in something, by present day all he is is an enforcer for Dounami who sold out his own cause and takes every available opportunity to satiate his sadism. In the past he tricked Nobuhiko into eating the remains of Yukari, whom he was in love with, and then proceeded to taunt him over it. In the present, Bilgenia gleefully murders people on Dounami's behalf, and commits other wanton acts of pointless cruelty, even go so far as to kidnap Aoi, forcibly turn her into a kaijin, force her mother to watch as he does so, and then force Aoi to watch as he murders her in front of her. Even when he sides with Aoi later on, it's purely to get back at Dounami and Nobuhiko and nothing else. It says something when Bilgenia is so vile, him getting kicked down by the above Hate Sink feels very well deserved.
• Kamen Rider Outsiders: Zein is a tyrannical artificial intelligence that puts up a front as a Benevolent A.I.. Given the franchise runs on Humans Are the Real Monsters as a recurring theme, Zein seeks to impose a zero-tolerance policy for malice. However, Zein's Knight Templar mentality causes it to have a warped understanding of good and evil, believing that humanity's capacity for malice is so persistent with no middle ground that it comes to the conclusion that it needs to Kill All Humans. Zein fully cemented this status in episode 4 after exposing itself as a villain. All of its narrative of benevolence and goodwill come off as a superficial excuse of a hypocritical and self-righteous despot with a God complex who plans to make humanity fight among themselves, and even sacrifice innocent people for the sake of rooting out malice. The reason why Kamen Rider Outsiders exists as a series that the main characters are villains from past series, it makes sense why the audience needs to root for them to be the only hope to oppose Zein.

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