Kappado is a member of the Akuma Clan and the main antagonist of episode 6 of Akumaizer 3.
He is voiced by Setsuko Wakui, who also voiced Blue Hakaider in Kikaider 01.
Kappado arrived on the surface to enact a plan to flood Tokyo by turning all the dirt in the city into water. The Akumaizer 3 soon arrived to battle him and he dueled Gabra while his Aguma soldiers fought the other two. After discovering Kappado was a water demon like him Kappado attempted to convince him to turn good and apparently succeeded, until Kappado stabbed his belly and revealed he was only pretending, cruelly rebuffing Kappado before exiting the scene.
Later, Gabra attempted again to convince him to turn good and again apparently succeeded, bringing Kappado to show Yoshiko and Jun, only for Kappado to reveal he was only pretending so he could find Yoshiko's laboratory and stop her from making any more of the serum which reverted his liquification. He kidnapped Yoshiko and attempted to take Jun as well, but he was scared off by Mitsuhiko, who made it seem like Darunia was there by using a fan to blow pink flower petals.
At his underwater base, Kappado showed Mezalord that he had captured Yoshiko and suggested that she could be of use to them, but Mezalord ordered her executed immediately, believing she would be nothing but trouble. The Akumaizer 3 soon showed up to rescue her and in the process defeated Kappado.