Oh, wow, I didn't realise it took Dogga this long to get here! I swear it was in the single-digit episodes... more importantly though it looks cool as hell; easily one of the best designs in the show

It's a very appropriate debut for sure. I'd also like to point out how the lightning backdrop in his finisher could be a metaphor for anger, symbolizing Wataru's anger towards the Rhino Fangire for sadistically destroying the dreams of his victims and attempting to do the same to his new friend. The other symbolism is of course Frankenstein but I mostly like what it says about how ticked off Wataru is in this scene. It's the same anger that Kiba felt when he fought Owl Orphenoch.

So let's address the elephant in the room.
https://i.imgur.com/wfg6q5c.png

Of course this has been common practice in previous seasons but I think it is worth talking about.
https://i.imgur.com/h3Ces4u.png

Personally it is interesting how certain design elements resurface in future seasons. Also fun to tease and comment how one iteration looking similar to the previous, etc. :lolol

Makes sense, honestly -- everything about Kuuga was perfect, so why not take a few leaves from its book? :p

Personal headcanon, due to Den-O's success the big bosses at PLEX orders their designers to do the 4 form changes again for Kiva. One of them skims through their archives and sees Kuuga and goes, why not. :lolol
I would like to add a reminder that the key difference is that Garuru is associated with wind and Bassha with water, while Kuuga Dragon and Pegasus is the other way around.

This Wataru right there, this reminds me of again Kuuga, which is Yusuke against Jaraji, the one he's pushed into brutally beating the monster with full of hatred. Though I don't think that this part is righteous for Wataru, or more righteous than the other times, while it's appropriate for Wataru to be enraged for this Fangire, I think if you're filled with hatred and vengeance for killing evildoers, it can be a fuel for.... becoming more and more severe in punishing until you end up like Nago (not that Wataru will of course, but sometimes these kind of monster can urge the hero to stain themselves while finishing them off in the process), giving excessive punishments to anyone that is bad just to make sure.

The "everything underneath that is still The Worst" is exactly about Otoya's heroism here, that is, Otoya is only concerned about certain people, which is women, that he wants to protect, but he'll be detrimental to non-women ones like for example males, which he'll likely be apathetic or potentially dangerous to them (the talk about Otoya's heroism, I'm more convinced for him against Oomura rather than Yuri, as he's womanizer), like you said, toxically masculine. Being a womanizer has either 2 outcome, being fiercely protective to any women and likely detrimental to non-women, or being detrimental to the women itself for the objectification and tactless approach (like Spider Fangire). Being caring and protective of your loved ones; friend or family, doesn't necessarily make you a good person, which is why I prefer to judge morality on what will they do to people less related to them like civilians or strangers, as there are villains that is revolved around their loved ones.

Nago gets his just desserts for shifting the blame for his defeat to IXA, which Shima pointed out that it can be Nago not capable enough to bring the best out of IXA :p. Other than that, it's seen again for Nago's self-righteous extremism, that he gives excessive punishment to a human criminal that even Megumi had to stop him as he can potentially kill the human. Again, unfortunately some people are like-minded with Nago here to kill anyone who does bad, because likely being influenced by media negativity to think the law is never competent even once for dealing with criminals (them getting off scot-free) for one of the reasons.

Yeah, it seems that Kengo reverts back to the more selfish part of him after initially getting to know Wataru's violin stuff, though I likely will give less flak about this as Inoue wrote Kiva from the beginning and this part's also done by Inoue (no clashing between different writers), but for the sake of conflict character growths can be ignored. I feel like Nago feels betrayed by Wataru that he feels Wataru is giving him false hope to become a pro rock star (as the manager turns out to be Fangire, and apparently, humans with burning passions has more life force for Fangires to consume). And yeah, new form for Kiva, the mighty glacier one in Dogga Form, a purple one too like Kuuga Titan. Dogga's main finisher is slamming the opponent with a projection of purple fist... but as Fangires crystalize when killed... it can be that the finisher attack is the shockwave that got released from The Eye instead.. although when I read other sources, the shockwave is meant to immobilze them, not killing the Fangire..

That would've been amazing, but I can't feel even a little disappointed with what we got. The blocking for that gag, with Otoya perfectly matching his choreography with the other dancers while Yuri tries to give a report over the phone to Shima... it's wonderful. It's so perfectly Otoya to not just try and cover up his injuries in front of a woman, but to go so far overboard in his faking that he's dancing in the streets. I loved it.

Yeah, for all the clever camerawork these episodes had, the final fight against the Rhino Fangire was sort of forgettable. But the way Kiva is 1000% not screwing around makes it still come through, emotionally.

One of the things it does, and it's a tiny detail that I love in Rider weapons, is that it changes form via physical manipulation. Like, IXA transforms it by hand between the two modes. It gives it such a playful, DX feel that I find it very charming and engrossing. I like the reality of it, I guess.

Yeah, this fight is personal to Kiva in a way that even Megumi's kidnapping wasn't. There's a sadism to the Rhino Fangire, a joy in crushing dreams, that's antithetical to Wataru's worldview. The Rhino Fangire needs to be erased from the world. It's an intensely cathartic finale.

(One tiny thing that cracked me up, though, is when Wataru gets to the Rhino's shrine. Wataru is looking for confirmation that the Fangire is preying on Kengo, and Wataru has to look over the entire shrine multiple times to pick out his best friend from a group of two dozen people. Is Wataru face-blind? Was he so stressed that he briefly forgot what Kengo looked like? It's a small thing, but it made me laugh just before the darkest part of the episode. I would maybe have edited that scene differently!)

One of the nicest things about the Nago scene is the way Shima and Megumi's tone communicates to the audience that everyone knows Nago is being a gigantic baby after losing to Kiva. He's folding his arms like a grumpy toddler, refusing to own his mistakes, and making everyone treat him with kid gloves. It was such a fun scene to watch. I like petulant and childish Nago! He's so weird!

The "why not" is because they made it too hard for me to pick a favorite of the bunch again. :p

But really, I think it ended up being great timing to reuse that concept, since Kiva was the last just kinda "ordinary" Heisei show before the big anniversary celebration Decade came along and then Double went on to create a new normal shortly thereafter. They essentially had the perfect amount of distance from Kuuga for it to not be redundant, and frankly, with a design aesthetic THAT radically different, you're not exactly going to mistake one Rider for the other. Seeing them all together like that in the image Sunred posted really gave me pause to think about how crazy the franchise had already gotten from that relatively humble rebirth in 2000.

I do really love the idea that Kiva's motif is just monsters, by the way? It's such a direct example of a Kamen Rider being a hero created from something evil, and then you throw in stuff like edgy rival Ixa as the light to Kiva's dark, ironically heroic in a way that's more creepy than Wataru could ever hope to be, and it's just so—

The theming in this show is amazing, is the point. This isn't even the first time I've gone on a tangent praising the aesthetics. Probably won't be the last, either.

Oh, and hey, speaking of!

I specifically remember being rather enamored by the Ixa Calibur when I was first getting into Rider. Weapons in toku that transform from guns to swords are a dime a dozen – and for good reason – but something about the elegance of the way this particular one changes shape entirely by jamming the magazine up into the rest of it really caught my eye. I feel like it's a perfect one weapon crash course on how fun, smart, and creative the toy designs in Rider can get.

Yeah, it's... it's kind of two things that I like about it? There's the fun, visceral nature of the weapon change: that CHONK of it switching from gun to sword, the slap on the magazine. That's just fun to imagine yourself messing around with.

But the other thing is sort of how cathartic that feeling is (it just feels good to smack that gun, exert some force on something), and how that reflects on what IXA means to Nago, and also how ingrained the idea of catharsis is to the show?

Like, Nago becoming IXA is an outlet. It's him shedding his human form in favor of a purer distillation of his worldview/psychosis. (YMMV.) Kiva is sort of the same thing for Wataru. It's him getting to express the aspects of his personality that he has problems articulating outside of being a Rider.

The IXA Calibur being a release valve for Nago is one of those little background touches that feels too aligned with the series themes to be accidental, you know?

Hey, I love to point out that the notoriously uncommunicative Kamen Rider Faiz draws his superpowers from a phone, so I'd believe it! Having designs that can also speak to the story is a ton of the fun of Kamen Rider for me.