UFO Robo Grendizer (1975)

Escaping from Vega's evil forces, the young Prince of planet Fleed leaves his destroyed homeland aboard the UFO Robot Grendizer, a powerful war machine, and makes it to Earth. Rescued by a bright scientist and fellow earthlings, he fights the saucers and robots sent by Vega, who plans to seize the mighty Grendizer and conquer the whole universe, or destroy it either.