When the first filming pic was leaked for Zero-One the Movie, people assumed Kamen Rider Abaddon as a Raider instead of a Rider. They specifically called it as "Inago Raider" or "Grasshopper Raider". I had personally believed it to be inspired from Shocker Riders.
Cinematoday had recently interviewed the staff who had worked on Kamen Rider Abaddon and they revealed all the above three to be true..
Kamen Rider Abaddon's Naming
Takahito Omori (Chief Producer) - "We were deciding the correct naming for the temporary named "Kamen Rider Inago". That was when Screenwriter Yuya Takahashi come up with this name (Kamen Rider Abaddon). Takahashi-san had written the lines for Esu in the movie referring Old Testament. Character names are mostly inspired from Old Testament".
Raider's Design for Kamen Rider Abaddon
Mitsutaka Inoue who is Bandai Product Planning Manager had revealed that Omori had actually told the Design Team that "This time Grasshopper Rider will appear in the movie", but due the design team had misunderstood with Grasshopper Raider.
Mitsutaka Inoue - "Due to some misunderstanding we took it as Inago Raider".
Usually Kamen Rider Kaijin's design will be given to Kaijin Design Artist, but this time since the Raider were considered pretty similar to Rider in Kamen Rider Zero-One, Plex was in charge of this. Plex is the company under Bandai Namco Group that designs the character & Item Toys.
Takato Yamashita (Designer from Plex) - "In order to focus on Rider's Design, I had assigned the Kaijin's (Raider) Concept & Design Rule to a different team. Masashi Hisada had worked on this since it was the order of "Grasshopper Raider". Later he got surprised to know this and said "It was a Rider?""
Inspired by Shocker Riders
Takato Yamashita (Designer from Plex) - "Since there is going to be large number of Inago Raiders, Hisada had put in the Shocker Riders design in Raider's Design Rule. Raider's body is only the colour difference of Vulcan and Valkyrie, we put the armor of the motif. He made it to look like a muffler by surrounding the suit with pipes. So with Shocker Rider's motif, the final design was more like a Rider"