Under unrevealed circumstances he retired from being a supervillain and married the super-heroine Merry, Girl of a 1000 Gimmicks. They had a son, who was also gifted with mutant abilities. Brain Wave briefly returned to a life of crime, and his wife left him. 

(All-Star Comics I #58, 59) - Brain Wave went mad from loneliness over his years in prison. He was obsessed with beauty because the world never showed him any, so he stole a number of works of art, and put them in an orbiting space station. He created an illusion of an idealized male body to wear as his form. He found Per Degaton in a soup kitchen, and was determined to return Degaton to his former greatness, secretly hoping Degaton could make him a new body that resembled his illusion. From the space station he informed the JSA that he was going to cause disasters in Seattle, Washington, Peking, China and Capetown South Africa that would cause a chain reaction that would destroy Earth. They shouldn't have been able to cope with the catastrophes, but disaster was averted thanks to the help of the Super Squad. The JSA and Squad confronted Brain Wave aboard his space station, and learned that he'd sapped the willpower of the JSA that they displayed in averting the disasters to return will and youth to Per Degaton. When the JSA had the villains on the ropes, Brain Wave used his mental powers to send Earth on a collision course with the sun, demanding they submit or see the planet die. Power Girl sent Brain Wave's space station toward the sun, overheating it and causing the villain to pass out and lose his grip on Earth.

His son blamed him for Merry's disappearance, and they were not on speaking terms for years. His son later became a superhero and took the name Brainwave, Jr. Brain Wave sacrificed his life to save his son from the psychic monster known as the Ultra-Humanite. In dying his final gesture of paternal love was to transfer the bulk of his mental powers to his son, the only legacy he could give him.