SET UP!!Kamen Rider X was the third Kamen Rider series from Shotaro Ishinomori, there was also a manga at the same time.Jin Keisuke is a guy living in Japan with his father and fiancee, his father is a famous inventor as well as a judo expert. His father has been working on a motor that could be revolutionary. However, the latest evil organization Government of Darkness(or GOD for short) wants the invention. Jin's fiancee is a spy for GOD and executes both Jin and his father, but not before Dr. Keitaro manages to SOMEHOW drag Jin Keisuke all the way into his lab and install the engine into him. Dr. Keitaro dies shortly after, but not before leaving his son the gear to become Kamen Rider X! X vows to destroy the Government of Darkness, and avenge his father!
Black Knight: Apollo Geist fits this description, only in red armor.
Bloodier and Gorier: Not quite to Amazon extent in terms of gore, but close, with enemies being sliced in half, decapitated, and impaled. And Jin Keisuke is bloodily executed via machinegun fire in Ep. 1. The manga of X however...is extremely gory at times.
Evil Twin: Government Of Darkness Rider (actually a camouflaged monster)
Fake Shemp: Riderman in The Movie is played by a suit actor, stock footage from the tv show and an uncredited voice actor.
Forgotten Phlebotinum: In Episode 2, Jin Keisuke suddenly uses a two-barrel blowdart gun. It takes out some attacking GOD minions and even saves the Kid Of The Week from being lynched. In spite of it looking like the coolest thing ever, it is never seen again.
To elaborate, the monsters in the second half are combinations of animals and historical figures. Hence you get Scorpion Geronimo, Ant Capone, and, of course, Starfish Hitler.
Non-Serial Movie: 5 Riders vs King Dark. It's supposedly in continuity due to bringing back Riderman, but can't fit well into the series at any point. Rider X still hasn't been upgraded in the movie, but already knows the Riders, while in the tv show he only meets Rider 2 for the first time after getting his upgrade.
Stone Wall: X-Rider isn't any slower than the other Riders, but he's built to withstand the deepest ocean depths, and is therefore very sturdy. (The others mostly have stylized chest muscles protecting their torsos - X has body armor.)
Comes to a head in SPIRITS, when a dude punches Keisuke in the face while untransformed... and breaks his hand, while Keisuke just gets a bloody nose which goes away in a few panels.
Stuffed into the Fridge: As a hasty means to resolve a story arc, both Ryoko and Kiriko, Jin's ex-girlfriend turned-traitor and her mysterious twin sister respectively, both die in Episode 8.