Dio’s mission to assemble a robot army is interrupted by the appearance of Dune, a formidable warrior who was once Luna’s bodyguard. Elsewhere, Casshern continues his search for Luna.

Casshern and his traveling companions befriend three children claiming to be descendents of Luna. When the youngsters are attacked by Leda, Casshern risks his own life to protect them.

Leda tries to convince Dio to accept Luna’s healing, but eternal life is no longer his obsession. Dio now lives only to fight Casshern - even if their battle ends in his own destruction.