Kamen Rider is no stranger to Darker and Edgier storytelling. When these villains show up, the chances are the stakes couldn't get even higher.
- In Kamen Rider Ryuki, Takeshi Asakura/Kamen Rider Ouja was the embodiment of this trope (formerly he was a serial killer). The Rider War consisted of thirteen riders fighting each orher to the death for a single wish that the real big bad planned to exploit for himself and it wasn't exactly puppies and sunshine, but before Asakura came on the scene, only one Rider — a clearly evil one, at that — had died, and the current 5 at that time weren't doing all that good a job at the whole killing each other thing. That changed once he became Ouja, and he's responsible for the bulk of the dead Riders. His first kill was Kamen Rider Gai/Jun Shibaura who was an Asshole Victim at best. The worst part came where on an attempt to kill Shinji/Ryuki, he killed off Kamen Rider Raia/Miyuki Tezuka, who along with Shinji were the nicest and actual heroic Rider OF THE SHOW. His third victim was Kamen Rider Imperer/Mitsuru Sano, who was tricked by Kamen Rider Tiger to attack Shinji, who (Tiger) literally stabbed him in the back, leaving him barely alive. Asakura found him (Imperer) and killed him just because his (Imperer's) Mirror Monster interrupted his revenge match against Tiger. (The worst part about this is that Sano had one of the worst tragic backstories in Kamen Rider history, and Ouja killed for just interrupting a fight. His last victim was his rival Kamen Rider Zolda/Kitoka who was an Anti-Hero at best though it was revealed that Kitoka died due to his cancer, so his butler fought in his place.
- His American counterpart in Kamen Rider Dragon Knight, Kamen Rider Strike/James Trademore/JTC was almost just as bad, minus the serial killer part, he was originally a hacker. As Strike, he had a few cameos, ultimately revealed to be Xaviax's dragon. When he first stepped into the action, he chased Kamen Rider Torque/Drew throughout the city for attempting to betray Xaviax (it's unsure if he wanted to overthrow Xaviax/have a Heel–Face Turn/or outlived his usefulness) with a badass Advent Bike. When he caught up with Drew, the two fought at the same time Dragon Knight, Wing Knight, and Sting were fighting Kamen Rider Thrust/Brad Barett to convince him to join their side, since Brad was a good guy, (compared to his Japanese counterpart) was framed by Xaviax for sabotaging another motor cross racer's bike. Knocking Strike down, Drew decided to use his ridicously powerful Final Vent, which hit all five present riders. No one got vented, but Thrust was severely hurt since Strike used him as a shield. Strike/JTC, knowing that Thrust was Good All Along, and would eventually perform a Heel–Face Turn, vented him. He caught with Drew again and in a epic battle, he was able to vent him. Five episodes later, he and the Cho Brothers effortlessly defeat Wing Knight and Sting and vent Sting when the latter sacrifices himself to save Wing Knight. In the next two episodes, he kidnaps Kit's dad from the hospital to convince Kit to join Xaviax, vents Axe for disobeying Xaviax when he went after Kit/Dragon Knight for venting his brother, and 3/4 into the series, vents Len's girlfriend Kase/Kamen Rider Siren. JTC actually managed to vent more riders than his counterpart could kill. This guy only gets taken down when, Len uses the Survive card to transform into his Super Mode, Survive Mode Kamen Rider Wing Knight, brutally combines a Curb-Stomp Battle, Roaring Rampage of Revenge, and a awesome Single-Stroke Battle like clash of Strike's Sting Final Vent and a variation of Survive Wing Knight's Final Vent. It took that much to vent him.
- Kamen Rider OOO is a goofy series about a homeless man fighting greed, but it soon got crazy when we meet Dr. Maki, learn his backstory, and find out about the purple medallions. Before Maki's appearance, there were legitimate villains, but the episodes were still Strictly Formula, and Maki is soon elevated to Big Bad status. Also a case of Crouching Moron, Hidden Badass, as Maki is portrayed as a socially awkward man who is obsessed with a doll he carries on his arm, becoming distressed whenever someone touches it. No one would expect him to effortlessly kill the other Greed.
- Kamen Rider Gaim has multiple instances of this trope, as there are multiple moments in the show where the stakes raise even higher.
- The New Generation Riders. While these characters are already present, them taking the center stage turns Gaim from a goofy show about dancing and Mon Battles to a show where the lead characters try to uncover a conspiracy involving the Yggdrassil corporation.
- When the Overlords arrive, it also becomes clear the world is at the brink of an apocalypse that could wipe humanity from the face of the earth.
- An inverted example is Demushu. The episode in which he is killed off is the episode in which the aforementioned apocalypse starts in full force.
- Kamen Rider Build: Blood Stalk starts the series as a seemingly Affably Evil Dragon with an Agenda. However, the series gradually reveals more about not only puts him in Faux Affably Evil territory, but also raises the stakes. First, it turns out that he's been running around manipulating all the various villain factions as well as the heroes into escalating the already brutal civil war that he helped start. Then it's revealed that he plans on completing the Pandora Box which could wipe out all life on the planet like it did with Mars. And it turns out that not only was he responsible for destroying Martian civilization, but also countless other planets for who knows how long. And the only reason he hasn't destroyed Earth yet is because he wants to gain a power which could let him destroy the universe. Combine it with his utter lack of regard for all other life, the fact that he becomes one of the most powerful beings in the franchise and wracks up on-screen body counts just as large, and you have a villain that contributes heavily to making Build one of the darker Kamen Rider series.
- Kamen Rider Outsiders is not for the faint of heart, despite being a spin-off where the bad guys are the main characters who have their own fair share of comedic moments. On the heroes side, Zein and its host, on the other hand, are the reason behind the anthology's darker aspects:
- The Yuto Sakurai who transforms into Kamen Rider Zein is a cold-blooded, murderous, nihilistic and somber Fallen Hero who is a far cry from the fiery temper and heart of gold of his prime counterpart. In his debut episode as Zein, Yuto viciously dominates Banno to the point he starts screaming in fear and terror before turning him into a Human Pincushion. Shockingly enough, this Yuto is more willing to cross the line in the name of a greater good of which most heroic Riders are not supposed to. Had he killed both Horobi and the Ark without Brain protecting them, he could've crossed the Moral Event Horizon. This Yuto serves as a cautionary tale of how a great tragedy can turn a hero into becoming the same evil they're fighting.
- Zein itself is completely devoid of anything lighthearted and lacking the humor of returning villains like Kuroto Dan. As soon Rin explains to Kuroto why the threat of Zein must be taken seriously because Zein exists everywhere. Zein placed the entire world under surveillance to the point evil organizations like Foundation X and Smart Brain end up on its watchlist, and it's just a mere indicator of what's to come. Zein finally cemented itself as this at the end of episode 4 by possessing its host, the aforementioned Yuto Sakurai as it tricks Genm Corp. into relaunching Kamen Rider Chronicle while impersonating Nico Saiba so it can proceed with its Final Solution to root out malice into motion, ending the first half of Outsiders with the entire human race under the mercy of a tyrannical artificial intelligence with little to no hope of opposing it, unless the heroes and villains get their act together so they can join forces to oppose Zein.
