Nico Saiba: You're going to use and discard them just like those cards...?
Horobi: So you're saying that you're using the Kamen Riders as a means for exterminating mankind?
Horobi: So you're saying that you're using the Kamen Riders as a means for exterminating mankind?
For a long-running franchise that runs on Phlebotinum Rebel as its recurring theme since 1971, the phrase "absolute power corrupts absolutely" is a cautionary tale even for the most heroic and righteous Kamen Riders, as well as villains who want nothing more but to satisfy their ambition and lust for power; in both ways, can become a clear and present danger to the entire world if left unchecked.
- Kamen Rider BLACK:
- Shadow Moon is one of the earliest examples in the Showa Era, hence why he's never called a Kamen Rider in any way. Unlike Kohtaro Minami who successfully escaped before he was about to be brainwashed, his stepbrother Nobuhiko Akizuki wasn't, and Gorgom made him as their most powerful enforcer, his first act as Shadow Moon was to slay Birgenia once the Creation King and the High Priests are now fed up with his failures. He nearly succeeded in killing Kohtaro in the end game episodes, but Kohtaro wasn't going to go down without a fight.
- The manga has an alternate Kohtaro Minami from a Bad Future turning out to be this, brainwashed by Gorgom to succeed as their Creation King and rule the Earth with an iron fist, especially with his power at its peak.
- Kamen Rider Kuuga:
- The titular Rider's aptly-named Final Form, Ultimate Form, embodies this trope, whose power is equal to N-Daguva-Zeba himself. So much that one Rider Kick from said form can reduce the entire world into a smoking crater. Yusuke himself became horrified by the prospect of becoming this trope after seeing visions of Kuuga Ultimate. Luckily for him, being pure of heart allowed him to control the form and ended up defeating Daguva in a fight to the death even after being de-powered.
- The aforementioned N-Daguva-Zeba, the series' Big Bad. He is the strongest of the Gurongi tribe, making him both revered and dreaded by his own kind, especially he has no compunctions at killing his own kin if they stood no chance against Kuuga.
- Kamen Rider Agito: The Overlord and his cronies justify this trope by killing any human that possess the power of Agito, viewing them as a threat to his power. Anyone who possess the power of Agito themselves go insane to the point of attempting suicide.
- Kamen Rider Ryuki:
- Takeshi Asakura/Kamen Rider Ouja is a human magnet for violence among the participants in the Rider Fight, existing solely to kill and maim anyone that vexes him, even his own family. He even manages to stack a number of kill counts in the series just to prove his superiority.
- The Mirror Shinji Kido/Kamen Rider Ryuga represents Shinji Kido when pushed to a dark path because of his desire to live in the real world, which allows everyone around Shinji to be easily fooled by his mirror counterpart. He proves to be a very terrifying opponent easily eclipsing the aforementioned Asakura, to the point of weakening him by slaying Genocider in Episode Final .
- Kamen Rider Kabuto has Issei Kurosaki from God Speed Love, ZECT's top assassin whose trump card is the Hyper Zecter, allowing him to outmaneuver his opponents. What he lacks in Hyper Form, he is able to make short work of Kabuto and Gatack until Tendou takes the Hyper Zecter for himself. Kurosaki represents Tendou if he joins ZECT to prove their evil plan and uses his status as The Ace to the extreme point of ruthlessness.
- Kamen Rider Kiva: King, the first Kamen Rider Dark Kiva is dreaded by other demons, including his own people. While already a stronger opponent as Dark Kiva, it's his Fangire form, the Bat Fangire that proves his superiority, requiring two different Kiva (one of which being his own Dark Kiva form used against him, under the usage of his son Taiga) to defeat him for good.
- Kamen Rider Decade: Tsukasa Kadoya, the titular Rider of the series' very existence is feared around the AR Worlds, to the point that every residing AR World Rider revile him as the "Devil". This is due to the fact that Tsukasa had a history with Dai-Shocker, and was originally its Great Leader. Matters not helped by the fact that he is called the "Destroyer of Worlds".
- Kamen Rider OOO: The ancient King was the original Kamen Rider OOO, unlike his heroic successor, he uses those powers in conjunction with the Greeed's stolen medals to further reinforce his dominion against the Spanish Armada that were assigned to stop his global conquest. It got to the point where he created natural disasters like earthquakes and tsunamis to level his opponents, a testament of how dangerous Eiji could have been if he has no restrictions to his powers.
- Kamen Rider Gaim:
- Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai: Kamen Rider Fifteen serves as one of Badan Empire's enforcers. Not only is he a Kamen Rider, he also has the Heisei Lockseed that allows him to harness all 15 Heisei Rider powers up to Gaim in a manner similar to Decade, the latter's brief duel with him further lampshading this situation. Had it not for Ryo Murasame revealing to have impersonated as Ambassador Darkness and freeing the Heisei Riders, Badan Empire would have successfully rule the world unopposed.
- Towards the end of the series, both Kouta and Kaito have transcended their humanity, becoming Overlords themselves. Kaito wants to remake the world in his own design where the weak can no longer be oppressed, with Kouta being the only one standing in his way to the point that two rivals have to duke it out for the fate of all humanity.
- Kamen Rider Drive: Both the Kamen Riders and the Roidmudes have the power to unleash Heavy Acceleration; a temporal field that slows down, or outright stop time at will by the use of their Core Driviars. The prospect of seeing one of the good guys using this power is basically playing fire with fire... with catastrophic results. Which explains why Krim forbids the heroes from using that ability; even Chase after redeeming himself, decided to stop using Heavy Acceleration, which he previously used a more powerful variant while he was Mashin Chaser.
- Kamen Rider Ex-Aid:
- Masamune Dan himself with the power of Kamen Rider Cronus. Having bid his time incubating the Game Disease within him while behind the bars, he returns to utilize Kamen Rider Cronus, more specifically through the Master Gashat that allows him to stop and rewind time to his favor while at the same time putting the lives of the other Bugsters within his leash by deleting them if necessary. It required the help of Hyper Muteki, the "Save" feature that Kuroto developed and eventually Dr. Mighty XX Gashat to actually outdo his machinations to the point of his eventual defeat in the final episode.
- Emu briefly toys with the idea in episode 39 when Masamune Dan forces him into a Sadistic Choice by killing Parado, doing so to save Nico from another Game Disease. Using Hyper Muteki, Ex-Aid completely obliterates Para-DX to the point of no retaliation, with even Poppy reacted in horror when the All-Loving Hero she used to know suddenly became as ruthless as Masamune did. The final nail on the coffin is when Ex-Aid cancels Para-DX's teleportation escape by holding him choke point and delivering the finishing move, ending with Parado yelling in agony as his life came to an end.Emu: There will be no next time. I will show you the ending you richly deserve!
- Kamen Rider Build: Evolt/Kamen Rider Evol is a Planet Eater that devoured many planets. For most of the series, he makes up for most of his cunning and long-term planning to set the plot of the series into motion. Once he regains his Rider powers, he becomes a more terrifying adversary, giving the heroes a hard time. Even so when he regains his Black Hole Form, which is far superior to Build's Genius Form.
- Kamen Rider Zi-O: Ohma Zi-O, the future self of Sougo Tokiwa, is the Overlord of Time who not only has Time Master powers, but also wields the power of all 20 Heisei Riders in his disposal (and later on extending to Showa and Reiwa Riders) and having brought the entire world to its knees as he rules over the Bad Future with an iron fist. Even to this day, Ohma Zi-O stands out as one of, if not, the most powerful Rider and Kamen Rider villain overall in existence.
- Kamen Rider Outsiders: Zein is an artificial intelligence that represents all the worst traits of every heroic Riders, taking their sense of justice to the extreme point of tyranny all for the sake of eradicating human malice, diminishing the concept of Kamen Riders and everything they stand for, not helped by the fact that Zein serves as a cautionary tale for authoritarianism, and its followers are more than willing to sell out mankind in exchange for a utopia of absolute peace and order.
- Kamen Rider Geats: Mela in the 4 Aces and the Black Fox movie is a future human like the rest of DGP's staff and audiences who obtains godlike powers by committing deicide on gods in recorded human history and obtaining their powers in return. Then this trope is taken to further level when he splits Ace, who at that point had awaken his godlike powers as Geats IX, and takes away 3/4 of his traits, by extension taking his own godlike powers too. This resulted in the creation of X-Geats, representing Ace if he abused his powers for villainy and moping the floor against Tycoon and Buffa in their strongest forms. After obliterating almost everything on Earth with the Jyamato tree, he would have taken Kouta's powers (who is also an embodiment of this trope at some point) had the Ace of Hearts didn't try to stop him.
- Kamen Rider Gotchard: The reasons behind Minato's siding with Geryon and the Dark Sisters also boils down to this, in addition to Fantastic Racism. He views the existence of the Chemies as a clear and present danger to the world. The events of Kamen Rider Gotchard × Geats — The Strongest Chemy ☆ Gotcha Grand Operation were the final straw for him, after seeing firsthand the destructive power of the Level 10 Chemies rampaging seemingly justified his fears should they fall into wrong hands.
