yeah, but still its a pretty imprctical thing to do. like the agito FFR. decade basically just rode it and slashed the baddie with the ridebooker.:sly:
Everything about Decade was impractical, why does he need so many range FFR weapons like Faiz Blaster and Kiva Arrow? Why does he need so many FFR vehicles like Kuuga Gouram, Agito Tornador, Kabuto Zecter, etc.
With regards to J turning into a Complete Form Decade, how the hell does that happen right? He didn't even have a gigantic K-Touch, only a gigantic DecaDriver.
Honestly, it's just the writers saying, "Hey! We could give Decade a taste of his own medicine! Turning him into a giant DecaDriver since Kabuto can turn into a giant Zecter, and make J wear him since he's size is relative to the giant henshin device!... Why? Because we can!"...
All in all, I can see Decade is supposed to be a Heisei Rider team-up which got overrun by the FFR toyline, which ultimately destroyed all logic.
Decade does need the riders there. Although, I think he could henshin into the rider, use the card on himself, but the only ones that would be practical with would be Ryuki, Agito, Kuuga, and Kabuto. Anything else, he would need Diend there to use.
So putting it like that, it seems what Decade was supposed to do, Diend perfected, by summoning the respective Rider and using the FFR card, then presto!
Decade really screwed up everything, tsk tsk...