Gatezone employs an extremely powerful yet extremely rebellious member of his machine army to use his machine-controlling powers to defeat Kotaro for the Crisis Empire.
Shigeru finds a strange green stone needed by the Crisis Empire to activate their new dimension-switching device as the daughter of the scientist behind it pursues him to get it back.
When Maribaron accidentally kills the Crisis Emperor's cloned daughter, she decides to fix her mistake by abducting the Sahara daughter, Hitomi, as her replacement.
Pursuing Maribaron and Hitomi in the Demon World, Kotaro is forced to fight against the assumed traitor Deathgaron, leading to a sorrowful encounter that awakens a new power in RX.
While still pursuing Hitomi, Kotaro encounters a strange cyborg who wishes to work on his side, but is under the control of a harsh, mind-controlling warrior of the Crisis Empire.
Crisis creates a second sun over Tokyo, forcing the city to burn unless a scientist can develop a special magnetic gun that can eliminate the threat while under Kotaro's protection.