The X Unit (Ｘユニット, Ekkusu Unitto)[1] is an attachment combined with the Birth Driver to become Birth Driver X (バースドライバーＸ, Bāsu Doraibā Ekkusu), and allows its user to harness the power of the Core Medals to transform into Kamen Rider Birth X. It was developed by the Kougami Foundation to fight Ancient OOO and the Greeeds, who were revived in 2021. It is later used as a conduit for the user to jump between different dimensions. The X Unit is composed of the following parts: Birth X can summon wea