Super Electromagnetic Machine Voltes V: Volume 18

Included:

S01E35 Requiem for a Soldier From the Stars
February 4, 1978 TV Asahi
Bernard, the husband of Nina, the woman who was brought together with her baby to Big Falcon by General Dange (episode #27), decided to visit his family in Big Falcon as well as testing a space ship made by Dr. Gou Kentarou. Unfortunately he was sighted by the Boazanians who were looking for the rebel's secret base.

S01E36 Attack the Underground Castle!!
February 18, 1978 TV Asahi
General Gururu came to Earth from Boazan to evaluate Prince Heinell's efforts in conquering the Earth. Meanwhile, the rebel slave's base in Alpine mountains was discovered and attacked. Dr. GOU Kentarou was kidnapped by Gururu right in front of Voltes V's nose. As Voltes chased Gururu, he led Voltes into Heinell's underground lair.

Note: All titles and names are different in the English version.