Decade use Data Cards due to the fact each card he use has specific data on the card to allow him to change to the rider and allows him to travel though different universe or worlds

Surprising they never thought to do a Nanotech Kamen Rider yet. Where the entire suit is contained within the Driver. Activates, and millions of little machines create the suit and weapons. Different Nanobots, different suits.

And it could work irl, given time. Nanotech does exist.

I recently came up with a mini theory. Borrowing the concept of the Morphing Grip form Power Rangers, I came up with the idea of the Rider Grid. It is a energy grid connecting ever Riders powers, and allows for a sort of equilibrium when Riders combine their powers. One example is in Climax Deka. It makes little sense for Castle Doran to be able to channel the energy from DenLiner and ZeroLiner. Castle Doran is an ancient, monstrous being. The Liners are vehicles that channel energies that alter time and space. But if the Grid exists, then it would equalize the frequencies of the two until they equalized and allowed them to perform an insanely powerful attack!

The original Kamen Rider were the results of genetic testing and cross specie gene splicing

Which could very well happen. But I see it happening less like the original and more like The First and The Next.

Kabuto's suits form up in a way that's reminiscent of nanotech sci-fi stuff, probably because of their mutual obsession with hexagons.

And nanotechnology is nowhere near that kind of thing yet. The more pragmatic option (if you can even think to call it that) would be something like Isaac Clarke's Advanced Suit or Iron Man's Mk V, where the armor kinda folds out over the limbs from a large pack. Even then, it'd be a really darn slow transformation to assure it wasn't pinching any skin or tearing out your hair.

The nanotech isn't there yet, I know, but it could be one day. Something like Kabuto even could be along the way. But instead of the Masked Suit appearing you physically put it on before leaving for the battle. Then it blows off for the more agile Rider beneath. MK V wasn't that slow, though. I mean it took about thirty seconds, and that can be a lifetime with monsters breathing down your neck. But it wasn't horrible.

Pains me. But the one I don't see happening is something like Fourze. Weapons appearing from a switch? Even OOO I don't see ever happening. Something like Kabuto, or The First though I do. We already do gene-manipulation. Wouldn't take much to make a Rider 1.

Well, if you physically put on the rider suit, that ruins all of the fun. Like with G3. The helmet was the most exciting part, and probably the least realistic, because that transformation would tear off more hair than a poorly-handled Cabbage Patch Kid. I'm not saying the Mk V was slow by any means, in fact all of Iron Man's suits are way too fast to be anything but fiction. That sort of fast transformation would just never work with human tendency to twitch and have little bits of ourselves sticking out every which where.

And I can get where you're coming from with the weapons. Space magic isn't the best excuse ever. Birth though, probably handled weapons in the most realistic way Kamen Rider will bother to do weapons. And Kabuto's weapons appeared in the same style that OOO's did. Out of thin air.

Now Faiz, Decade, Den-O, Riders like that handled weapons well. Faiz just converted his Cell, Decade's Booker just pulled out into a Gun/Sword, and Den-O constructed his sword from peices he already had. Always appreciated that.

I see your point to about MKV. One wrong twitch and you lose a finger or so much worse. I think Kabuto is a way around that, soon as we figure out the nanotech.

Some really interesting theories here. I'm never one a fan of using science to explain Toku because no matter what, there's always something that is wrong enough to ruin suspension of disbelief. It's like how Star Trek fans often wage war in interpreting what is scientifically accurate while struggling to explain away scientifically problematic stuff.

But well, my science sucks so perhaps I'm biased that way. :lol