February 16, 1974
It is a special episode which acts as a recap of the Kamen Riders up to X-Rider, as well as featuring the return of Shiro Kazami (Kamen Rider V3), who will assist X in his fight against G.O.D..
Following the return of Shiro Kazami (Kamen Rider V3) in the previous episode, it debuts a permanent upgrade for X-Rider.
Keisuke accidentally helps Dr. Yan daughter and entrusts her to Tobee. However, the true identity of the girl was the monster Centipede Youkihi. Kamen Rider X raids G.O.D.'s hideout to save Tobee who was taken hostage. Kamen Rider 2 and Kamen Rider V3 also join the battle.
Finally, G.O.D. gets all the blueprints of Dr. Nanbara's RS Device and completes it. Kamen Rider X challenges a deadly battle to destroy the device at the expense of his life. However, as the G.O.D. attack intensifies, the giant Kingdark finally begins to move...