Iwao Himuro
The head of ISS and a major player in the syndicate. He appears to be a kind gentleman, but is truly a heartless man. He is slaughtered by Shin after he guns down Ai.

Goushiima / Cyborg Soldier Level 2
Himuro's confidant and henchman. He is actually a Level 2 cyborg, an outdated cyborg model. He is decapitated by Shin.
Giichi Onizuka / Cyborg Soldier Level 3
Kazamatsuri's partner, with the plan to create a fusion of grasshopper and man and be their ruler. He is killed by CIA agents, while sending a telepathic plea for help to Shin as he dies, burning.
Series:  Shin Kamen Rider: Prologue