This is one of two new Kamen Riders who will appear in the Zero-One Others: Kamen Rider MetsubouJinrai (ゼロワン Others 仮面ライダー滅亡迅雷 Zerowan Azāzu: Kamen Raidā Metsuboujinrai).

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Kamen Rider MetsubouJinrai
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The first one is the titular protagonist; Kamen Rider MetsubouJinrai (仮面ライダー滅亡迅雷 Kamen Raidā MetsubōJinrai), the fusion Rider form of the MetsubouJinrai.net core members (Horobi / Naki / Jin / Ikazuchi) by transformed with another variant of Hiden Zero-One Driver; the MetsubouJinrai Driver (滅亡迅雷ドライバー MetsubōJinrai Doraibā) and its Massbrain Zetsumerisekey (マスブレインゼツメライズキー Masuburein Zetsumeraizukī).

There is one fact for Kamen Rider MetsubouJinrai: it is a retool of Kamen Rider Horobi's suit with additional head, torso, arm, and shin armor.

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Kamen Rider Zaia
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The second one is Kamen Rider Zaia (仮面ライダーザイア Kamen Raidā Zaia), the main antagonist of the film. Its true identity is none other than Leon Arkland (レオン＝アークランド Reon Ākurando), the CEO of ZAIA Enterprise Headquarters who attempts to mass-produce Humagear soldiers to sell as weapons across the world. To do so, he kidnaps Jin as a part of his plans.

He transformed into Kamen Rider Zaia by using the ZAIA Thousandriver and unlike Thouser who was using one each of Progrisekey and Zetsumerisekey (Amazing Caucasus and Awaking Arsino), he inserted the Triceratops and Carnotaurus Zetsumerisekeys simultaneously instead.

There are two facts for Kamen Rider Zaia:

・Its suit is a repaint version of Kamen Rider Thouser and reuses Kamen Rider Ark-Zero's bodysuit.

・The first Reiwa Kamen Rider who has a Dinosaur Motif and the first Kamen Rider since Kamen Rider OOO Putotyra Combo.

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Fighting Scenes and New Raiders
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There are some fight scenes from the movie.

・Kamen Rider MetsubouJinrai Vs Kamen Rider Zaia

・Kamen Riders Horobi, Ikazuchi & Naki Vs Kamen Rider Zaia

・Kamen Rider Zaia with the Raiders. The blue one is based on Wolf (Shooting Wolf) and the  Orange / Red is based on Cheetah (Rushing Cheetah). Behind them, there are Panda & Buffalo Raiders.