He Was in Leo and Became the MAC Vice-Captain at the Beginning.

Ultraman + Kamen Rider + Passionate and refreshing novel Introduction: Accidentally traveled to Leo's world, obtained the Ultra Fighting System, joined the Earth Defense Force due to the original owner himself, and unexpectedly became the deputy captain of MAC, replacing Leo as the new guardian of the earth. During this period, monsters appeared one after another, and a black mist always sneaked behind to strengthen the monster. Its appearance caused the plot to deviate from the original route. After repeated battles, the mastermind behind the scenes gradually surfaced, and it was none other than Diablo-Dark Zaki. With the emergence of Dark Zaki, Leo's later plot fell into a state of collapse. In order to defeat Dark Zaki, Rei Takadera found the King of Ultra and obtained mysterious power from him, joining forces with Leo to defeat Dark Zaki. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.