Dreams...what all men and women have... aspirations for good and for evil. On twin worlds, the course of history... two doctors desired to manipulate minds to feed their own demented desires.
Doctor Destiny aka John Dee was originally a scientist devising anti-gravity discs and will-deadening devices, which he employed versus the Justice League. When these and his elaborate scheme failed to subdue his adversaries, the Doctor employed his greatest creation in the Materioptikon. This mechanism allowed him to materialize the dreams of his opponents. After a series of confrontations, the League placed mental blocks in place so that Dee could no longer dream, and thereby activate his virtual Materioptikon stored within his mind. This caused his body to wither and resemble a skeletal husk. It was at this point that Destiny adopted a costume much like that of other supervillains.
Brain Wave aka Doctor Henry King was originally a psychiatrist who had the ability to materialize images from the minds of others and other gadgetry. Using devices to tap into the nightmares of his adversaries, he embarked on a decades long rivalry versus the Justice Society. After long being ridiculed for his miniature appearance and having been kept from works of beauty during a lengthy stay in prison, Brain Wave created a new virtual body with a more traditional supervillain costume.