I really don't see Bisharp as a Sentai/Kamen Rider-type character at all, if anything he's more of like a armored samurai dude or something. I think people kind of jumped on that too fast.
I consider Ledian and Accelgor more homages than he is. Ledian strikes me as having a "sentai-like" helmet, and he also has Iron Punch and a lot of punching moves fitting for such a hero. Accelgor has the scarf, Hi-Jump Kick, and the show even gave him an episode that was a Kamen Rider Homage for the 40th Anniversary, complete with Shocker Grunts (based off Vannilite).
