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The Berotha Magia is a HumaGear that was hacked to turn into a Magia and an antagonist in the first episode of Kamen Rider Zero-One. He was originally a HumaGear named Gut Buster Taro before the MetsubouJinrai.NET operative Jin hacked him by placing a ZetsumeRiser on him.
Gut Buster Taro was originally created as a comedian-type HumaGear to entertain people. After delivering a humorous performance to crowd, Taro was approached backstage by Jin, who forcefully placed a ZetsumeRiser onto his waist which caused him to go haywire.
Taro then went back out to the audience and turned into the Berotha Magia before hacking the other HumaGears around him and going on a rampage. However, Kamen Rider Zero-One soon showed up and defeated him.