Episode 21, "Grudge! The Longest Day at Kurogane House: Part 3"
*****SPOILERS*****
Synopsis: Tsubasa summons the arm of Zeus from its hiding spot- the Japanium ore pile underneath the Photon Power Labs. The pilot of Energer Z is revealed to be Count Brocken, who activates its self-destruct program to combat the arm. Thanks to a computer program on board the Mazinger, Kouji is able to use the power of Zeus’s arm to destroy the Energer Z. To protect herself from being targeted, Tsubasa invites detectives from across Japan to protect her at the Kurogane House, along with the returning Kurogane Five. Also returning is Akokuji, who brings with him a reprogrammed Gamia, as well as news that the real Kenzo Kabuto is still alive. As they prepare for the upcoming battle, Dr. Hell attacks with Bardos Island itself.

