Yes, thats could be possible if Grateful debut in episode 23 because Takeru already enter to Ganma World. Idith already hold All Takeru's Heroic Eyecons and Eyecon Driver G is almost complete. Also, in Ganma World, we have Makoto (has 3 Heroic Eyecons) and Alan (Has 2 Heroic Eyecons). So, something can make Takeru successfully to collect 15 Heroic Eyecons.

In Kamen Rider Ghost, we have Network Corporation, Deep Connect. And...sometime I am has feeling if Deep Specter Ghost Eyecon come from Deep Connect's research.... Hmm...since Deep Connect leader already possessed by Ganma and under Igor's orders, and Deep Specter Ghost Eyecon design based from Ganma belt....
Furthermore, Igor is Scientist.....so yeah, maybe Makoto obtain Deep Specter Ghost Eyecon from Deep Connect Corporation.....

Actually, we've already made that connection. For those that haven't yet, you excluded since you just said something, I wonder why they haven't. It's a blatant connection and setup.

Hmm....yes, I am has this feeling because Igor also in Deep Connect Corporation. So, maybe Igor create Deep Specter Eyecon.....

Hmmm...sometime, I am also has feeling if Makoto will battle against Takeru again because corrupted powers from Deep Specter Ghost Eyecon....

That's pretty much every new rider series now a day. Too many cool forms for nothing.

I can accept that. I was having a little trouble noting the differences between the forms. But I think you got it down. Hopefully we'll get to see them get used more in the future.

This question on TGL made me want four Ghostbusters themed Riders for the summer movie all over again.

I believe Edith and Sennin are the same man. Orchestrating events for the upcoming final battle. Adonis could somehow be orchestrating it too. They're using Takeru, Makoto & Alain for something bigger.

DAMMIT. Looks like the Jyuuouger crossover is gonna be canon. And a pretty important episode too. I hate it when that happens.

At least it not that bad

I am not a fan of whole dimension idea

I heard Ninninger came from another dimension where Kamen Riders doesn't exist!

No no no no! I rather want Toei to do Marvel Cinematic Universe-style to both Super Sentai and Kamen Rider! Both of them are Toei's national treasure! Without them, Toei wouldn't made so much money! That's my opinion!

Damn!