Casshan (1973)
Original title: 新造人間キャシャーン
Casshan is a 1973 Japanese-language animation series. It stars Ikuo Nishikawa, Emiko Tsukada and Osamu Kato.
Dr. Azuma creates robots to benefit mankind, but they unexpectedly rebel and begin to destroy everything in their paths. To deal with the catastrophe, Dr. Azuma's son volunteers to become a human robot, even though he knows he will never be able to return to human form again. He confronts this grave situation to ensure a bright future for all humans.
Where to watch Casshan
Stream: HiDive