I may or may not annoy some fans of the older era stuff with this, but Igadevil hit on something that's been bugging me for some time.
Part of my big problem with Decade, or at least with the last movie, is how they can't seem to settle on just what Decade is.
Now I love the idea of him being the ultimate weapon, created by every Rider villain teaming up to destroy the Riders, and he's forgotten. Perhaps the big battle in episode 1 wasn't a dream, but could have been the moment when Decade (and the universe) was shattered- leaving him stuck on a backwater world with no memory of who he's meant to be until the chance arises for him to atone. It's simple and to the point. It makes sense with the original idea- Decade travels the worlds, makes friends, acquires more power, but when he reaches the end and the chance to reclaim the life he lost, he has changed along the way going from a villain to a hero. It's like an unintentional redemption.
Unfortunately there's everything else. The whole self-fulfilling prophecy/Decade must destroy to save/worlds colliding/stories and memories things really doesn't jive with the other explanation. It might have come first, but I think it's the less-cool one.
I can buy that Daishocker could create the ultimate Rider who, despite a moment of weakness in trying to re-assume his old life, realizes what his journey was really about and accepts his place in the Rider family. I have a harder time buying that Tsukasa's response to being attacked by the 9 Heisei Riders is to go apeshit, turn everyone into cards, get a new mask for some reason, then let Natsumi kill him so he can save reality and come back with some CGI assistance to go help Double fight the all-new, all-annoying Neo Organism.
As I said the first time, I think Movie War was trying to go for a metafictional angle, but it really doesn't work. It's got some good ideas, but the whole thing really doesn't hold together with what's gone on before. It'd have been more satisfying if the final revelation was that Decade is a TV series. Narutaki is just an angry internet fanboy, complaining about Decade ruining his favorite shows and injecting cameo appearances wherever possible. The show ends with Tsukasa walking off set as the lights turn off and Yusuke raiding the commissary. That would have been total bullshit, but it'd be bold. What we have feels kind of limp, as if they had planned a more spectacular ending and then did something completely different. Oh wait...
So I suppose you can say that if you go with the idea of Decade as Daishocker's trump card, I think he could theoretically be able to beat all the Riders... though in practice, he shouldn't be able to. If Decade should have swiped anything from Spirits, it's the idea that ultimately, the STRONGEST RIDER EVER!!1!â„¢ still sucks as long as he's evil. I think especially to that part where ZX and Rider 1 kick each other... and it's ZX's leg that shatters. He's the Perfect Cyborg, but he's playing on the wrong team. Evil simply can not ultimately triumph over Good in the Riderverse. He might be newer and shinier than Rider 1, stronger and faster even. But at that point he lacks the human spirit that is Kamen Rider's real greatest strength.
My biggest problem with Decade is this right here. The Heisei-era Riders are quite simply...too powerful. Its not about special effects or whatever BS some old-school fan will try hide behind...its about concepts.
Kuuga, by the end of his series, appears nigh-omnipotent. The random-ness of him setting his enemy on fire in the finale kinda signified to me that the Ultimate Form came with all kinds of new powers that we just never saw because the final fight scene wasn't about him being horrendously strong so much, they just wanted to show you how powerful he had become.
The whole point of Agito is to show the near-infinite ability of the humans to grow and adapt, and Agito is the embodiment OF that, AND his powers come from the creator of humanity himself.
Blade's powers allow him to tap directly into the proto/archetypical animals of the planet. Not only that, his Ultimate Form allows him to tap 13 of those powers simultaneously, when its already been shown that most people have trouble using the powers of 1, much less 3 or 4, and its shaky at best.
Den-O...the fact that Den-O has ANY powers and can become a Rider at all is based on the fact that he's a singularity point. That means no matter how you alter, change, or rewrite time, Ryoutarou will ALWAYS exist.
(I have no idea what Faiz or Hibiki's powers are, and Ryuki's powers aren't nearly as impressive as those four, and Kabuto's were tech-based to begin with, while Kiva's powers don't even NEED to be emulated to be defeated in the first place.)
My point is, apparently Dai-Shocker is able to not only emulate ALL of these powers, but put them all into ONE single device, and I just don't feel like evil should ever have that level of power--particularly an evil which, up to this point, specialized in making really powerful cyborgs who they repeatedly would forget to brainwash when they made particularly powerful ones.
Its...an insult, really, to the Heisei Riders. Like saying, "Hey....these are the Showa villains. They're IMPORTANT. Who cares what you can do?"
And you know...it might have been okay if Tsukasa had been a Yuusuke/Shouichi/Kenzaki-type of guy. Heisei Rider has a habit of giving the really ridiculous levels of power to the super-nice, heroic-type guys. (With the exception of Tendou, which is probably why so many fans reject him being so strong.)
It would have been perfectly FINE if the Decadriver had been made by Sumiko Ozawa, who created the G3-X armor (which could keep up with Agito, who smacked around Agents of Creation), with the help of all the other Riders/smart people in the Rider-verses. That would have signified a level of respect, and acceptance from the other Riders that Decade HAD powers that surpassed theirs and could destroy everything.
But they didn't do any of that. Instead, Dai-Shocker just collects all these powers like they're Pokemon, and shoves them into the Decadriver because, well, they're Dai-Shocker and they get to do that. Regardless of how much sense it makes, plotwise.
Around this time, someone's going to tell me Dai-Shocker's made up of former HEISEI villains. Which is true, but...ugh. That was a mistake too. The Grongi would just see a group of Dai-Shocker's level and enjoy playing a "game" with a group more interesting than humans. The Unknown, and their boss, would notice Dai-Shocker has the power to traverse universes, declare it frighteningly close to the ability to evolve, and attack. The Mirror Monsters would not team up anyway, as they're not very intelligent. The Undead don't care about any game except the Battle Fight, with the exception of a few Royals. And the villains from Den-O exist to destroy timelines anyway; why would they team-up to fix them so they can rule?
The purpose of any group is that they have, to some extent, similar motivations and goals. Most Rider villains, honestly, simply do not. And YES, you could create reasons why they would. ...But Decade didn't, and left that to fans because kids don't care, housewives don't care, and the fans should just suck it up even though this series is supposed to be for them. If this were Decade's only flaw, I'd excuse it, but its just one flaw among dozens in this series. (Like how Clock Up is MUCH faster than the speed of sound, what with how easy it dodges bullets, but somehow Faiz's Accel Form cold keep up anyway...)
And THAT'S why I asked this question. Because in my eyes, while Decade COULD defeat all ten Riders, as he exists, I don't think he deserves to.