Perhaps I would have preferred the situation with Mashin Chaser and Kamen Rider Chase, where the main theme of the character is retained after becoming a rider.

So far it looks very similar. The school is on the poster and Hasegawa wrote Gridman, where the characters are also high school students.

Also, doesn't this secondary pseudo-rider simply dismiss rumors of Decade's involvement with just his looks? I mean, is it possible that both the secondary and tertiary riders will both be pink?

All the rumours have added up so far and Valbarad isn't really a rider so far, if he becomes one he could easily lose those colours or they get less emphasis like Chaser did

I see. That would sound cool too I guess.

My opinion on the 101st Gotchard card, which does not fit into the "10x10" scheme of the show. It is clearly intended for the final form (which it will create on its own or in combination). My options for what can be depicted on it:
1) Philosopher's stone - the main goal of all alchemical research, fits thematically and bestows immortality, which will clearly help create a strong final form.
2) Life, the Universe, or something equally global that can unite the previous 100 cards.
3) Kamen Rider. I hardly believe in such an option, except perhaps as a form for a summer film. But for the trend "the final form is similar to the base" is suitable.

Hasegawa also wrote nearly 16% of Fourze, penning 8 scripts for the show, so he definitely has the potential to channel that Fourze energy for Gotchard

Alright guys here's some Gotchard toy leaks translated from 5ch (leaks come from someone called color), see images for details & again grain of salt.

"Gold color Decade". Apparently, Tsukasa turned into Agito too often. All in all, it definitely won't be Decade by the description. Even if it's Inoue and it's Tsukasa, the differences are enough to make it a different rider.

Yellow could be extinct animals in general, like how Kaiserbee matches with something called "Charis", so that could mean anomalocaris. I totally agree about pink though, as "Oni" would easily fit in that category. Although Hibiki would argue it's a job.

Speaking of Hibiki....

Considering how Hibiki was a commercial failure, they might just skip to Reiwa Kabuto instead. Like how Zero One the Reiwa Kuuga was followed by Saber the Reiwa Ryuki.

Which means this pattern doesn't actually make sense anyway, cause there's nothing to compare to Geats.

All I can see is Don Momotarou.

Part of Kamen Rider Club's activity does give them the opportunity to leave campus sometimes, especially after Ohsugi gives his approval. Maybe Gotchard will also be some kind of school function.

Nice observation!

Not quite 100% yet. The rumor of a pseudo turned out true, sure, but there's no evidence to suggest he'll eventually upgrade to Secondary.

I'd hope they handle the upgrade from psuedo to Rider differently, as I disliked the aesthetic of Kamen Rider Chaser losing the uniqueness he had as Machine Chaser. The white of Mach and the silver of Chaser made the group dynamic look too much neutral to me.

Your first 2 options sound plausible. I'd also suggest the concept of "void" or "quintessence", a mysterious power that exists beyond our material realm.

Sounds like my prediction about the attachment allowing 10+ sum cards might turn out true!

Congrats on your 1400th post!