These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: Is Haruto a male Pollyanna who manages to be relatively positive and well-adjusted despite his tragic backstory, or a bland, personality-less cutout? Are Koyomi, Rinko, and Shunpei a decent supporting cast or a bunch of annoying hangers-on with nothing to do aside from being cheerleaders/kidnap victims? Is the story having a good time while slowly building itself up to something awesome, or is it all flash with no real substance?
Opinions are fiercely divided on Mayu. Some are ecstatic that we're finally getting another in-series female rider, while others are upset that she's little more then a glorified mook. Though most of them can agree (albeit wrongly) on one thing: she's a goner.
The Myna Bird arc has created this for some people. Is it a nice Breather Episode filled with lots of laughs to hold you over while its final arc begins or is it an Idiot Ball filled two-parter that ended on a harsh note for some people?
Complete Monster: Hellhound. While Phantoms aren't saints, he builds up Shunpei up then humiliates him on national television, rubbing it in how he'd managed to play him for a fool. But instead of just torching his book himself, like Minotauros did with Daimon's locket, he possesses Shunpei and makes him do it to drive him across the Despair Event Horizon. What makes him stand out is the absolute glee Hellhound takes in doing all this, laughing while Shunpei sinks into complete despair.
Wiseman, or whoever set up the eclipse ritual in the first place is a nasty piece of work too. It's bad enough that he/they abducted people and drove them to Death by Despair, but to have a child (Koyomi) involved... Similarly, a few episodes after we discover this; Phoenix, Medusa, and Wiseman target an even younger kid by assaulting his parents. The fact that they're so casual about this makes Phoenix's attack on the staff and patients in the hospital mere insult to injury.
There's Phoenix himself too. The guy is a complete psychopath who outright admits he only wants to go after a Gate so he can cause carnage and havoc For the Evulz. He proves he's this after Rinko accidentally gets him to throw off Wiseman's orders. Phoenix responds by nearly killing her and ends up destroying a large section of the city and holding the rest hostage to bring Haruto out to fight him. Is it any wonder Haruto calmly condemned him to aFate Worse Than Death by throwing him into the sun?
Beelzebub, possibly even worse than Phoenix. His method is to brainwash the friends of Victim of the Week to first alienate them, then has Shunpei and her husband physically abuse her as well. The worst part? He outright admits he's drawing all this out, destroying her life one piece at a time, because he enjoys it. Most Phantoms try to break their target the quickest way they can, Beelzebub purposefully takes it slow and draws it out For the Evulz.
Legion trumps even Beelzebub! Whereas Beelzebub's interpretation of fun is breaking someone's life one little piece at a time, Legion's interpretation of fun is finding someone who is "beautiful" (not in the appearance sense, but rather the metaphorical sense), entering their Underworld (regardless of if they're a Gate or not), and destroying them from the inside out. So yeah, he also trumped Phoenix in that regard.
If its any indicator, Phoenix and Beelzebub were both allowed to roam free. Wiseman sealed Legion away because of how Ax-Crazy he was.
Gremlin/Sora may be the worst yet on the basis that he was already a Complete Monster before becoming a Phantom. To elaborate, he was a Serial Killer who'd been responsible for a number of missing person cases, and he still occasionally engages in his 'hobby' as a Phantom. What makes him even worse is that in the episode before, he saved her life, implying that he had noble intentions, only to be revealed later that he wanted to kill her himself.
The previous Kamen Rider, Gentaro Kisaragi, stated that he lost his parents in a car crash, but kept his optimistic personality and made lots of friends. Haruto on the other hand also lost his parents in a car crash, but got Survivor Guilt when he survived and they didn't. Three guesses as to which Kamen Rider is suffering the most.
Remember back during the Lizardman arc how they had to not let the Gate know what really happened to her boyfriend? Well, cut to the Myna Bird arc, where we see what would have happened.
Yamamoto from #46-47 is played by Todoroki, and his wife (Miyu Sawai) was Pretty Guardian Sailor Moon. His love interest back in Hibiki, Hinaka (Miyuki Kanbe), also held the role of Sailor Moon before! What drives this straight into Tear Jerker zone is that while Yamamoto's wife very nearly died here, Miyuki Kanbe passed away for real.
Not only that, but certain events revealed in the endgame of the show have caused similarities to be drawn between the two Rider shows that Madoka is compared to.
Ironically, whereas it's a plot point that the people who fall into despair are female in Madoka, the female-to-male ratio of Phantoms, who are monsters born from Despair, is staggering... Only two females were ever Phantoms.
Wizard getting attacked by his own dragon apparently foreshadowed the upcoming cameo by Wakana Matsumoto aka Airi from Kamen Rider Den-O, after which a different dragon (Ryuutaros) will be after his blood...
At the start of the series, many believed and hoped that the secondary rider would be female, this would turn out not to be the case, but then in #24, Kosuke, in an attempt to hide his identity from his grandmother while fighting as Beast, adopts a high-pitched voice and pretends to be a girl. Then Grandma Nitoh assumes that Koyomi (who some hoped would become a Kamen Rider) is Beast.
However, as of #27, Mayu, Misa's sister, is taken in by White Wizard to be his apprentice. She comes back at the end of #41 to face off Medusa as Kamen Rider Mage.
Karma Houdini: Depending on whether you're sympathetic to Sora's back story or not, the Karma in question was being a part of the Sabbath Ritual, where he becomes a Phantom instead of being killed and impersonated by one. He still dies in the end of the series though.
"Bitch, Please." Sometimes "Flame (or whichever ring), Bitch."
Comparisons between the White Wizard's Hamel Cane with the Dragon Dagger.
Mood Whiplash/Dude, Not Funny!: The ending of #37 mixes Nightmare Fuel with Crowning Moment of Funny in a way that causes motion sickness for some. While the Gate breaking up in despair is supposed to be a comedic punchline, the fact that his face cracks in the most scariest way possible, followed by how in the other times it happened (especially the last time, where it's used as a villain's Moral Event Horizon), it's meant to be more scary and played with no comedy whatsoever, and it's like the writers forgot that this is supposed to be a bad thing.
If Phoenix didn't cross it when he nearly killed Hiroki's parents, then he definitely did it when he tried to burn Rinko alive after convincing him to stop taking orders from the Big Bad.
Medusa crossed hers in one fell swoop, first by revealing to her Gate's sister that she killed her parents and caused her to cross the Despair Event Horizon, and then by preventing Haruto from helping Mayu and forcing him to watch as she succumbs to despair.
Gremlin/Sora passed his in his backstory before he became a Phantom as well as solidifying his Complete Monster credentials with the revelation that he was a sociopathic Serial Killer. His moment afterwards? How about killing Koyomi?
If not there, he definitely crossed it be going on a rampage through Tokyo, on the rationale that the Gates will be driven into despair and become Phantoms and the normal humans will just die. What makes it worse is how much Gremlin's clearly enjoying every second of it.
Where was Wiseman's, you ask? Was it when he turned his own daughter into a vessel for the Philosopher's Stone? Creating the Phantoms in the first place? Holding the Sabbath? Manipulating everyone and causing countless murders and deaths for the sake of making Phantoms and Wizards? Kidnapping someone?
Most Wonderful Sound: The repeated 'infinity' chant can be heard as this to some instead. This is because the only time it happened is when Haruto first become Kamen Rider Wizard Infinity Style.
Narm: Shabadooby touch Henshin!, which quickly becomes dissonant during the more serious fights. They don't happen often, but when they do, it kills the drama like no other.
The creators themselves seem to have become aware of this — lately, they appear to be doing their best to cover up the sound effect by blasting the Ominous Choir soundtrack over it, and in #19 he actually swipes the ring the moment the switch is turned, jumping the gun.
As of episode #39, they've been forgoing the sound effect entirely.
In episode #46, White Wizard is fighting against Gremlin, and is essentially clobbering him. White Wizard strikes the finishing blow, and Gremlin dramatically falls to the ground...only for him to immediately stand up again and run off.
Paranoia Fuel: As shown in the first episode, the Phantoms can impersonate the person they were born from almost perfectly. The person who was your friend, partner, or family member? They could've been driven over the Despair Event Horizon and killed, then replaced by a monster seeking to do the same thing to others, all without you even knowing it!
Replacement Scrappy: Gremlin, who is pretty much Shunpei for the villains. Some think he isn't as awesome as Phoenix. And then he got Rescued from the Scrappy Heap for people and got a lot more terrifying when it's revealed that he's still got his humanity, or what's left of it considering his human self was a serial killer.
Haruto from Alternate Universe.
So Okay, It's Average: At least in the West, this is the prevalent opinion on the series; not outright bad, but just not that good, mainly due to it's bland lead, annoying supporting cast, uninteresting villains and CG-overdosed fights.
Firstly, we could have seen whether Phoenix could survive death after Kamen Rider Beast or Medusa absorbs mana from him.
Secondly, the Myna Bird arc ends with the Gate succumbing to despair, but almost nothing comes out of it. He doesn't become a new Phantom and not even having Haruto or Nitoh go in his Underworld and slaying his Inner Phantom... Just going to the next episode that's completely unrelated.
Thirdly, Dragon becoming a Phantom made of hope shot down the whole "using the Dragon Forms increases the chance of Haruto falling into Despair" idea and showing consequences for using the Dragon forms.
Special Effects Failure: It's only for a second, but when Bahamut is defeated, he can still be seen lying on the ground after he explodes.
In 49, Haruto struggles with a handcuff that he could obviously just slip his hand through.
What an Idiot: Sure, Beast, trust what the Phantom tells you without question. They couldn't possibly be lying.
Continuing with Beast, you have to wonder if the ancient Wizards were smoking something funny when they made the Beast Driver by making its main Finishing Move be based on luck. Nitoh counts as well, since it's been shown that his Kick Strike is much more reliable than his Dice Saber.
The Untwist: Hands up, did anyone not see it coming that White Wizard was Wiseman? It didn't help that this exact same plot of a rider's mentor being affiliated with the villains but having a distinct anti-villain goal was repeated time to time.
The Caitsith Phantom has a number of negative stereotypes, which probably wouldn't raise eyebrows (even in the States) if they were given to a Jou Schmo but since they were all applied to a black man...
He's a slacker that only wants to do the bare minimum work required, and only because Phoenix and Medusa threaten him. The idea, it seems, was that Cait Sith was acting so lazy because he's a cat, but...
He's also homeless and living in a junkyard. (Though remember that we're talking about Japan, a country that is notoriously hostile against foreigners (as much as possible without getting outright xenophobic). A black dude could be jobless and homeless simply because no-one would deal with him out of prejudice.)
The translation by Fansub group Over-Time gave the Caitsith Phantom a more street language not seen from other characters (possibly some kind of attempt to make him sound foreign), which didn't really help anything.
The conclusion of the Lizardman arc is a particularly offensive example. We learn that Chizuru, the Gate of the week, was infatuated with a young man named Satoshi, whom she knew from her college days. Unbeknownst to her, Satoshi is actually Phantom and is currently targeting her in order to make her fall into despair. To prevent this, Haruto kills Satoshi's Phantom, then feeds Chizuru an elaborate lie, telling her that Satoshi has left the country and wants her to move on with her own life without him. The moral of the story is, as Rinko so aptly puts it towards the end: the truth doesn't always give people hope, so it's better for for them to live under a false reality just so long as it keeps them happy. Wo~w.
Though for this case, we know what would happen if the Gate was told the harsh truth instead, and this was reinforced when another, male gate falls into despair from a similar scenario.
Values Dissonance: Many Western viewers see Nitoh putting mayonnaise on donuts as a Squick moment...but Japanese style mayonnaise is much sweeter than Western style mayonnaise and probably wouldn't be half bad on donuts.
The Cait Sith Phantom did not want to make any Gate fall into despair and was not even interested in making new Phantoms. Like any cat, he just wanted to slack off. On the one side, he's forced to go after the Gate under threat of death by his superiors, especially when it was shown he couldn't hide nor flee from them, and on the other side, there's Wizard ready to swoop in to finish him off. The guy just couldn't catch a break.
Jerkass Woobie: Of course the guy was the one to suggest they just kill the Gates outright and forgo the despair part.
Mayu is a more straight example. Not only did her sister die and in her place as a sadistic monster, but then her parents were killed by said monster. Soon, she gets targeted as a Gate and her whole world turns upside down. It's hard not to feel sorry for her when she starts breaking down into tears.
Iron Woobie: Then, she has the phantom starting to grow inside her, but instead of giving into despair she forces it back. Why? Because she refused to let Medusa, an impostor of her twin sister, get her way. Now the White Wizard training her to be an apprentice so that she can avenge her family.
Yuzuru also had the same trappings as Mayu. He nearly fell to despair after seeing that he hurt his friend, but stopped when he saw that she was better, making him an Iron Woobie... Unfortunately, his woobieness continues when he doesn't want to be a Wizard... Good luck with that, buddy.