Honganji being the first of the Special Investigation Unit to defect and the one who inspires Shinnosuke to step up and be a hero like the original Riders. Assuming his age matches actor Tsurutaro Kataoka, Honganji would have already been 18 in early 1973, when Shocker would have fell if not for Kamen Rider 3's incursion. He likely only joined the Shocker-aligned Special Investigation Unit to serve as The Mole.
In the two-on-two fight of Drive & Rider #3 vs. V3 & Riderman, Drive ends up with #3 having to bail him out when Riderman tangles him with his Rope Arm. In other words, Shinnosuke was literally on the ropes.
Bald and sporting a white moustache, this film's image of Tobei Tachibana is derived from the manga incarnation rather than the familiar TV version. However, Tachibana's aged-up appearance combined with Rakkyo Ide's natural features does allow for the viewer to see him as what Akiji Kobayashi (1930 - 1996), who would have been 84 when this film was released, could have appeared as had he lived to reprise his role.
