Finishing my watch of the 90s Kamen Rider films is 1994's Kamen Rider J.
This is something of a different beast from Shin and ZO. It replaces the urban setting for untouched wilderness and swaps the medical horror for a numinous spirituality. It's very Ferngully-ish.
"The Fog," migratory aliens who last visited the planet 70 million years ago when they ravenously devoured the dinosaurs, have returned. The "Fog Mother" is close to hatching a new brood which will wipe out human life. However, before they do so they must first ritually sacrifice a human. To that purpose, the Fog Mother's children find two people camping in the mountains, Kana and Kouji. They kidnap Kana, while Kouji gets tossed over a cliff.
Kouji is saved by spirits of the Earth, who grant him the J Power with which he can transform into Kamen Rider J. He goes off to stop the Fog and save Kana, accompanied by awful puppet grasshopper, Barry.
J travels from unspoiled wilderness into more developed and polluted terrain fighting each of Fog Mother's children in turn, eventually approaching Dracula's castle the "Machine Beast Mothership." There are some fantastic suits, decent choreography, and the goop is here. It all culminates with the Mothership transforming into a giant monster, whereupon J turns giant himself, leaps into space, and does a diving kick from the stratosphere. It's not quite a chaos dunk, but it's close.
As fun as it is, I don't think it measures up to ZO. It's probably the best produced (and best paced) of the 90s films but nothing sticks to your ribs. The film exists entirely within the "conveniently abandoned location for fighting" with very little evidence of any larger world. None of the characters really have "traits" or "distinguishing characteristics" or "a personality." The setting is so removed and the villains are so allegorical that the conflict feels immaterial. You're here for the effects and the fight choreography.
In comparison, ZO had Dr. Mochizuki build an evil science base in a processing plant in the middle of a open-pit mine and it begins with its big evil monster building itself a robot body from junkyard detritus. That's a much more effective way of communicating "a callous attitude toward nature is dangerous" than a spirit of the Earth just saying so, and in ZO it's barely a tertiary theme. J is actually about the mistreatment of nature, all it amounts to some images of construction vehicles and vague sexual danger against a preteen girl.
Speaking of which, the film's treatment of Kana is uncomfortable. For the first half I presumed she was Kouji's younger sister but then its revealed that she's just some wandering preteen he happened to meet while hiking? Who has since been accompanying him for however long?? And now lives with him at his camp in the mountains??? And while thankfully never explicit, she clearly represents unspoiled nature in a manner that gives clear connotation to being sacrificed to the Fog. It's not great!
It's an unfortunate mar on what is otherwise a decent enough film and ends the 90s Kamen Rider films on something of a sour note.