The use of unadjusted Thunder Key caused GekiRyuKen to be in a state of shock, and Kenji fell into an inability to transform. In such a case, a tremendous magic wave runs in the town of Akebono City. Suddenly, a huge Jack Moon's Castle that appeared in the sky started the attack. The explosion occurred in various places by the ray which was shot indiscriminately! Hiding in shelters, among the feared people, the old town chairman called for a decision. The people of the town who stood up got on the fighter jet and headed for Jack Moon's Castle.
Quando o lado negro de Yack Moon desperta, fazendo com que o espadachim use sua fortaleza para atacar Akebono, Kenji precisa superar suas capacidades e utilizar a recém-adquirida Chave Trovão, alcançando a forma de Ryukendo Trovão para parar o insano vilão.