i m thinking the mysterious ojisan in KR ghost (he always giving hint) is somehow actually is the emperor in Ganma world...

both zombie and parad don't have the chibi head at the back because they don't have level 1

but why Ex-Aid level 10 (or 20? because XX) have?

You are just comparing, blind with nostalgia. The franchise has its own merits and unique. If you hate something just stop there it won't change anything, because you don't have power to change or stop it. They will doing whatever they want with the kamen rider and other franchises.

This day, Japanese tv have a regulations and rules about violation, gory bloods & death in kid/family show. They also got laws can't ride modified motorcycle in public road.

That's why they releases V-Cinema, Amazon Prime exclusive & Toei Premium series etc. for the director & writer do whatever they wants.
Example.. Ex-Aid Toei Premium; Kamen Rider Brave got unexpected violence, sexy girl showering & running with towel in public, blood, and more with Asakura returns (I don't need to post pictures for f sake to proves). Many Rider V-Cinema & other exclusive series got serious moment, drama, violent & blood for adult fans.

Left to right: Kars, Josuke and Joseph

This "reset" thing kinda confusing a little.. So it's not going back time but it's just the gashats reset to before the existence of Hyper Muteki Gashat.. I guess the gashats reversed to previous 6 or 7 episodes before Muteki Gashat been developed.. Probably why Proto Gashat returns back to Masamune.

While Gashat Trophies remain untouched even though KRC got reset... weird