Kamen Rider Zaia (仮面ライダーザイア) is a Kamen Rider exclusive to Zero-One Others: Kamen Rider Metsuboujinrai.

Lyon Arkland (リオン アークランド) is the CEO of ZAIA Enterprise USA and later CEO of ZAIA Enterprise Japan. He developed the Sold Humagears, soldier-type Humagear meant to fight in wars in place of humans.

Kamen Rider Zaia is a rider based on Kamen Rider Thouser, using the Triceratops and Carnotaurus Zetsumerise Keys and the ZAIA Thousandriver (ザイアサウザンドライバー). His abilities are nearly identical to Thouser, with the exception that he does not need the Thousand Jacker to absorb enemy rider powers.

First appearance: Zero-One Others: Kamen Rider Metsuboujinrai