Decade lost his memory after getting into a fight with Gackt.(Note well: This theory came from someone on YouTube.) In the PV for the opening "Journey Through The Decade", toward the end, Gackt shoots a white energy at Decade. That was how Tsukasa lost his memory. Gackt wiped it.
The entire series is The Plan on the part of Yusuke, Shoichi, Shinji, Takumi, Kazuma, Hibiki, Tendou, Ryotaro and Wataru.Or, to explain further: the nine universes merging on top of Tsukasa and the Hikari family's home universe ARE the universes of Kuuga through Kiva, but they aren't the ones Tsukasa is visiting. Instead, he's being sent to Alternate Universe versions of them to build up Decade's power. The real Heisei Riders are Stalling for time against the Big Bad until Tsukasa becomes powerful enough to ensure their victory; this explains how they could somehow delay the merger (as the real Wataru says in the first episode) even though such abilities should have been beyond all of them.
Yusuke Godai was killed fighting the Big Bad, and Yusuke Onodera will replace him.How else can they get around Joe Odagiri's well-documented feelings of Old Shame towards his time in Kamen Rider?
Yuusuke has been replaced by a Worm.However, it can't transform because it wasn't able to copy the part of his belt that starts transformation sequences.
After the final world, the group is going to go through the worlds (which have decayed) in reverse order.After putting down the last mural, the old man is going to have to turn the chain the other way to put them back up again. They will go up one at a time and when that happens the group will end up visiting the other Rider Worlds again in reverse order. Only to find that things have got worse. Why worse? In the second Ryuki World episode, Narutaki tells Decade that this world has been destroyed as well. Whenever Decade leaves a world, he destroys it.
Decade's Complete Form is the Demon that Narutaki talks about.And then he starts destroyin' shit for real. Alternatively, eats sea cucumber.
Narutaki is an older Yuuto SakuraiThey both wear long coats and cloth caps.
Narutaki is linked to the Great Leader (of Showa Rider series)...to help tie the Showa and Heisei rider series together! Decade's main movie is a team-up movie containing all the riders.
The Shocker Orgnisation (of the original Kamen Rider series) is the real reason the nine worlds are mergingThe Heisei and Showa Riders will be appearing in a team-up together, and Shocker will be among the enemies. The Shocker wants to destroy every rider at once, so they're destroying their worlds all at once by merging them together.
Kivaara's change in appearance is because she has been away from her own world for too longIn the same manner Digimon (in season 2) got weak if they were away from the Digital World for too long, Kivaara has been away from her own world for too long and is beginning to resemble a toy.
The red shoes system exists in Kabuto's worldSouji became aware of the red shoes system and decided to remove it from his Zecter; however, while doing so, he unwittingly destroyed the system that causes Clock Over.
Tsukasa will Face-Heel Turn (possibly against his will)Based on how his actor was wearing a DaiShocker jacket in the movie press conference. In the picture where the Shocker generals are posing, you can see the Shocker logo with the letters DCD in it. Why "possibly agaisnt his will"? See "Decade's Complete Form is the Demon etc." above, given that (apparently) he'll be out of control.
There are only two real Riders in the movie preview scene.They are Decade and DiEnd. Rest of them are copies summoned by DiEnd.
Gackt, not DiEnd is making the Showa Riders beat up Decade.Gackt has been confirmed to play Riderman in a magazine scan. In a last ditch attempt to make sure Tsukasa doesn't regain his memories, he convinces the other Showa Riders that Decade will destroy their world as well. This is why they're beating him up in the promo material.
There is a painting of the Power Rangers Universe in the photo studioThe painting consists of six streaks of colored light heading out of the Command Center, and heading towards the Astro Megaship. but it is not hanging in the rotation.
There are paintings of every single universe ever made in fiction in the photo studio.However, they are taken off the rotation when the group learns in the Shinkenger world to not let a non-Kamen Rider character get their hands on a Transformation Trinket, lest they transform into a super-powerful, distorted Rider and that world gets sent to hell by the ensuing distortions. (This is an easy premise for fanfic writers to abuse. If you want a Kamen Rider crossover, this is how to do it!)
Tsukasa has been visiting the original universe for each series.The episodes of Kamen Rider Decade that take place in Shinkenger's world are shown to take place in the same universe as Samurai Sentai Shinkenger. However, it still has slight differences from what is shown in Shinkenger (i.e. the roll call is different). Thus, all of the differences between the worlds Tsukasa visits and those shown in the original series are due to his very presence altering reality.
The reason Daiki knows all about the worlds and their treasures is that he's seen them on TV.The worlds everyone have been visiting are shows within shows in the other worlds (in the same manner Doctor Who is a fictional television programme in Eastenders and vice versa). Daiki watches the shows and then goes to the worlds to steal the stuff.
Natsumi will become a rider.Having been infused with Tsukasa's life energy.
Narutaki will also become a rider.It is rumored that the Dark Decade in the Climax Heroes game is implied to be Narutaki.
Another Tsukasa will be Dark Decade as he declares he is the real Tsukasa.Sort of true. He's not Dark Decade, but he is indeed an evil version of Decade. His eyes look different.
Decade is an Uchuu Keiji
In the finale the riders beating up Decade were not Kamen Riders for real.A Kamen Rider would never seek to kill another rider in order to save the multiverse, so the Riders who beat up Decade in the finale weren't the real Wataru or Kazuma etc. They're clones made by DaiShocker to get Decade out of the way of their plans of destruction.
One of the "New worlds" (non-heisei worlds like Nega, DiEnd and Shinkenger) would be The World of Knight
Tsukasa, Natsumi and Onodera Yuusuke are all Singularity Points.Partially evidenced by the fact that they were all possessed by Imagin at varying points, but also evidenced in Yuusuke's case in particular because he is the only alt-world Rider shown in the finale to have survived the merging of the worlds.
The Kuuga World containing Yusuke Godai was the first to be destroyed by Decade's creation.This is why he didn't show up among Wataru and Kazuma's comrades. He was killed prior to the start of the series, prompting the remaining Heisei Riders to band together.
Dai Shocker is made up of the remaining members of the organization that menaced the Showa Riders, and Tsukasa is an officer who was promoted to the leader of Dai Shocker.Shocker's great leader had a completely different type of voice and appearance, and in Black RX he was finally defeated. So Tsukasa is not that great leader, but a new one created from a fringe group of the remaining members of the organization. The recreated villains (Shinigami Hakase, Apollo Geist, etc...) are all clones or replacements of the originals.
The merging of worlds wasn't Decade's fault, it was 2003 Shredder's fault.To reiterate: In Turtles Forever, 2003 Shredder learns about the existence of the Teenage Mutant Ninja Turtles multiverse and then attempts to erase all of it from reality. This has nothing to do with Kamen Rider at first glance, no? Well, there's one single link to it all: Ninja Turtles: The Next Mutation. As much as Peter Laird hates it, the reveal of the TMNT multiverse effectively allows it to still exist somewhere in that cosmos. With that in mind, remember the Next Mutation crossover episode of Power Rangers in Space? Now that we've linked TMNT to PR, note that Mighty Morphin' Power Rangers had a three-part Poorly Disguised Pilot for... Masked Rider. That show, while being a hackjob, is nevertheless a Kamen Rider series, and so part of the multiverse etablished by Decade. Therefore, when Utrom Shredder began the destruction of reality... ONORE, SHREDDA! (And if you bring up the argument that Masked Rider became a Show Within a Show in Power Rangers Time Force, there's still another backdoor: the Rangers' connection to Super Sentai, which leads to the Shinkenger crossover in Decade...)
Decade will end up destroying all the worlds, and in the process create the World of Double.The reason Double contains so many shout outs to the original is because it's actually the reincarnation of the original Kamen Rider. His appearance in the movies seem to counteract this, but considering how the last three series (Kabuto, Den-O, and Kiva) all featured time travel in some way, how he got there could be semi-reasonably justified. Rather, the fact that he just randomly appears, kicks Shadow Moon's ass, and leaves seem to indicate two things. One: He seems to know what's going on despite having never met Decade or any other Riders. He's one of the few Rider's that don't outright attack Decade or call him a destroyer. That's because from his point of view, Decade's the one who created the world. Two: He's much stronger than the other riders. Shadow Moon could fend off Decade, the Double Riders, and Kuuga Rising Ultimate, but got totally curb-stomped by Double. Why is this? Simply put, if all the other Showa and Heisei Riders belong to one universe, and Double is the sole Rider in another universe, then conservation of ninjutsu dictates that Kamen Rider Double must be as powerful as EVERY OTHER RIDER IN THE UNIVERSE PUT TOGETHER.
The Diendriver was created for recon purposes.Think about this for a second. The reason why Daiki acts like a coward is because the Diendriver was not made for battle. This explains why it has an attack ride card made for the purpose of cloaking the user. It also explains why the driver summons riders. To distract any unwanted attention while the user escapes. It has a Final Attack Ride card for the purpose of dispatching said unwanted attention.
Since Natsumi's grandfather was a Dai Shocker kaijin, and is really her biological grandfather, she is exempted from the dreaded Epileptic Trees that befell female Kamen Riders.
Dai-Shocker reverse-engineered the technology from the Gosei WorldIt wouldn't be above Shocker to steal from the gods (or the nearest equivalent). The technology was modified slightly so that it worked across multiple dimensions rather than multiple "planes" of a world. Perhaps karmically, in stealing the power of the gods, they ended up creating a devil.
The Epileptic Trees already got to Natsumi.She was Den-o so the Trees had enough of an excuse to do away with her.
The Hikari Studio was one giant shoutout to Super Mario 64In Super Mario 64, paintings are used to depict the worlds, much like the studio. There was about 16 worlds in the game. Tsukasa and the gang traveled through 16 worlds in the show.
The title Destroyer Of Worlds is not referring to Decade himself, but the thing Dai-Shocker reversed engineered.Yes, Another "Dai-Shocker reverse engineered this" WMG. This time, they RE'd a Bokurano robot. Hence the title.
The merging of worlds was actually caused by the Crisis on Infinite Earths.At the end of Co IE we are told that the multiverse which was supposed to contain every universe was destroyed with the exception of a single world which was made of several other worlds fused together. In reality only universes possesing related sets of heroes were merged, the related DC Universe worlds became New Earth, the fused world of Decade was the result of the related Kamen Rider universes. Kamen Rider Fourze: Kamen Ride - Fourze, Form Ride - Elec, Fire, Attack Ride - Rocket, Drill, Launcher, Billy the Rod, Hi-Hack Gunnote , Final Form Ride (Rocket Drill) and Final Attack Ridenote . The DecaDriver basically repeats the phrases from the Fourze Driver in its own voice and timing. For Wizard, Please is added after "_____ Ride" to use magic. Kamen Ride Please - Wizard Flame, Form Ride Please - Land, Water, Hurricane. His Final Form Ride is the Wizard Dragon. Yeah. As in Decade pulls out the Dragon Phantom from Haruto's body, while the body forms the wingtips and tail. Gaim: Kamen Ride - Gaim (Orange Arms), Form Ride - Pine, Ichigo. What this means of course is that the K-Touch will need a new card - instead of the 10 Heisei Rider symbols, it's a "kataka-numerical" keypad that lets Decade punch in the first syllable of each Rider's name, letting Autocomplete save him some time.
DiEnd's Final Form Ride is a gigantic DiendriverThis didn't happen in All Riders vs. Daishocker because there was no one to trigger his transformation. That, and having a gigantic Decade wielding a gigantic Diendriver and assisted by all of the other riders would be the Rider equivalent of a Reality Breaking Paradox.
The Kamen Rider Decade story is an alternate universe of the Pokemon Colosseum universeTsukasa is Wes. Natsumi is Rui. Diend is Gonzap. Dai-Shocker is Cipher. Apollo Geist is the Shadow Tyranitar. The AU Riders are the ordinary trainers using Shadow Pokemon. Narutaki is Miror B. Ambassador Hell is Ein. General Jark is Venus. King Dark is Dakim. The Combatmen are Cipher Peons. Evice is Shadow Moon. Nascour is Colonel Zol.
Natsumi Hikari is the alter-ego of Ika-Musume.There is a running gag in 2ch and Pixiv that Ika-Musume is the daughter or the granddaughter of Ikadevil, so if Eijiro is Ikadevil, then Natsumi is Ikamusume.
In the 40th anniversary movie Tsukasa will be the one who will bring all the riders to the final fightSince he can cross through the worlds he's the most efficient way of getting them all at the same place.
The DC and Marvel universes are A.R. worlds.Jaime Reyes (a young man who was meant to be part of a conspiracy to take over the world uses his powers to turn into a bug like robot to fight the conspiracy) is the DC Rider. Johnny Blaze and Danny Ketch (brother bikers who were given dark powers that allow them to transform into superpowered forms with which to fight evil) are the Marvel Riders. Since they are both B-List heroes in their own world, live in the US and don't speak Japanese they along with Drex and Kit Taylor never attracted the attention of the major players in the Dai-Shocker/Decade/Rider conflict.
A American Adaptation of Kamen Rider Decade would have a guest appearance in Power Rangers Samurai (Which is the American Adaption of Samurai Sentai Shinkenger which has Tsukasa and Kaito appearing in at least one episode of Shinkenger)
Tsukasa gave himself amnesia.He did it in order to befriend the riders and, when he regained his memory, convince them to fight each other. This plan, oddly enough, worked out spectacularly.
Kaito's stealing is to create an army to save his world.Notice how most of his treasures are weapons and/or Transformation Trinkets. Things that wouldn't have any reconized value on worlds other than where he stole them from (and could be potentially dangerous since riders crossing worlds apparently destroys them) and even then they couldn't just be sold on the standard black market. He wanted to create an army of Kamen Riders to fight the Roaches and free the brainwashed masses of his world. It wasn't until after Tsukasa had helped him kill 14 that he realized that brute force couldn't save his world and he became less focused on stealing and more focused on messing with Tsukasa.
Natsumi's dream in the first episode wan't a future dream about the rider war, she was seeing a rider war that already happened.She's not seeing the AR world riders fighting each other and the Tsukasa from the series, she's seeing the original nine Heisei Riders and allies fighting Great Leader Tsukasa. The nine of them got wind of Daishocker's schemes and teamed up to stop him. Unfortunatley Tsukasa curbstomped them all, though they all survived. Except for Yusuke Godai, who is the Kuuga we see go Ultimate and fight Decade. When their two rider punches clash, Godai is killed and Tsukasa's decadriver and ridebooker are thrown into a different world, while Tsukasa himself is hurt badly enough to get thrown into Natsumi's world and loose his memories. The surviving eight Heisei Riders decide to take advantage of Tsukasa's amnesia and manipulate him into saving all the worlds and alternate riders, getting himself offed in the process. Thus they save the worlds and get rid of a major threat in the process. They just didn't count on amnesiac Tsukasa legitimatley turning good and still viewed him as the guy who kicked their asses and killed Godai. That's why they were fine with Tsukasa kicking the bucket for their plan.
Decade failed the worlds all merged anyways.Let's Go Kamen Riders shows no alternate world traveling needed to bring together all of the Kamen Riders just forty years worth of time travel. This means that by the time of this movie all of the AR worlds have been pulled together into one single world. They just happened to be mistaken that the worlds merging would destroy them, it just allows for bigger Rider Kicks.
Nega World is really the Mirror World from Ryuki.Pretty obvious, Nega World had Ryuki mooks all over the place, and Decade could use Ryuki's mirror-diving ability out of Ryuki World, so Mirror World isn't restricted to the Ryuki-verse because it's a legitimate world on its own.
Natsumi is the most powerful Rider ever.Why yes, I did just claim that, in Kamen Rider's forty-year history and notorious track record with female Riders, the strongest Rider ever is a woman. On what grounds, you may ask, do I make this bold claim? It's quite simple. Name one fight, one single, solitary fight, that she's lost after becoming a Rider all her own (i.e. not just being body-jacked by Den-O's Imagin.).
Narutaki is Tsukasa's Enemy WithoutMore specifically, he's Tsukasa's guilt and self-doubt, for both his actions as Dai-Shocker's leader and his inevitable role as the "destroyer of worlds". Narutaki blames Tsukasa for everything and tries to push his friends (or at least Natsumi) away from him because part of Tsukasa feels the exact same way, even if he's too cocky to really admit it.
Decade visiting the remaining Showa Rider worlds makes his hair resemble all the members of One Direction.
The Rider Trial in Ryuki's world is really a Minority Report style settingRemember when the Judge declared the Rider Trial was a logical system? He wasn't talking about the constant in-fighting where the winner would decide the fate of the person on Trial, he was talking about how it would lead into the trial not even taking place at all. Why? One word: Odin. Odin possesses the Time Vent card, roams around waiting for a Rider to fight him, and gives them the card upon defeat. Using the Time Vent card, they could go back in time and, with the evidence they're given during the trial, are able to stop whatever happened in the first place, or mess things up and cause the trial to repeat with different outcomes. And it's inevitable that they will have to fight Odin, since it's still There Can Be Only One and Odin is one of the participants.
Decades World of FourzeWould be a world where the other riders existed, but now Fourze, Meteor and Nadeshiko are the only ones left. Meteor is Fourze's senpai as a rider. Instead of the modules and switches of the show, this world's Fourze has the Legend Rider switches, though he does also have access to the Fusion States and a Cosmic States which uses all the Legend Rider switches. If they want to be more referential the Fourze technology can be developed by the same people as Super-1, and the Kyodain of this world can be more like the originals