Then it would've been Otoya with Kivat Bat II all over again.

What if Alternative had his own version of the survive card?

What if Godai and Onodera met?

What if the AU Blade riders had met the Riders of the world of Diend?

What if Diend had some stable character developemnt?

What if Decade hadn't left me with so many questions?

What if Narutaki was the owner of the DecaDriver?

He would commit suicide?

He would sit in a corner, depressed, insulting himself.

Narutaki doing something that requires true effort? Nah...

I imagine they'd get along quite well. I admit I've only watched the first four episodes of Kuuga before I lost interest, But Onodera seems to be one of the Decade riders most similar to his counterpart.

Now some of the other counterparts meeting might be more interesting, like the Agito riders meeting Decade Agito, who is a combined version of all three. Or the Human Dad/Fangire Mom main Kiva meeting the Fangire Dad/Human Mom Decade Kiva.

The Agito/Agito meet up would be crazy.
The Kiva one would be inetresting too.

I always assumed Kenzaki and Kendate would get along well, that would be cool to see.
Gotta rewatch Blade's arc one of these days.

What if Megumi is really Wataru's half-brother?
What if IXA had properlly used the Fake Sticks and killed Wataru?
What if Kamen Rider Kiva made good on everything it promised?

That would be lovely.

I don't remember the Fake Fuestles very much (being used once :P) but I suppose Wataru would simply stop using the Arm Monsters.

It would have been overbearing, it introduced too much stuff, there's no way to integrate everything well.