Heinous Helmeted Headmasters

Brainstorm and Thinker, Steve Dayton and Hartford Jackson, four scientist that developed cranial hamlets that enhanced their mental resources. The first two men used these devices for evil, the second two for good. But there two other men who likewise harnessed similar technology… Mister Esper and Professor Gaunt.

Mister Esper was a con man who had devised a super sonic whisper device that could induce his victims into following his every suggestion. With this technique at his disposal, Esper even temporarily stymied Batman and Robin of Earth-One in their attempts to defeat is ill-gotten ways. Nevertheless, the Dynamic Duo was successful in circumventing this, although Esper returned when he was employed by a Syndicate to finish the Batman. However, Esper manipulated various enemies of the Dark Knight into protecting the hero and his sidekick, and later made another play as Brainwash versus the pair, which ultimately led to defeat. 

Hiram Gaunt was a university professor who theorized the concept of a helmet which could augment a person’s brain power. When rejected by his fellow professors, Gaunt developed the device on his own, which gave him modest telepathic abilities. With this new ability, he began his criminal career first seeking out those who scoffed him, then once eliminating them he became a crime boss known as the Answer Man. This drew him into conflict with Sandman and Sandy of Earth-Two, who eventually defeated him 

Years later, Mister Esper returned under the alias of Captain Calamity, He was capable of tapping into the mental abilities of the young heroine known as Lilith through his helmet,  allowing him to unleash disasters from coast to coast across the United States. With his new mental abilities, Mister Esper could be on one coast of country while his projected duplicate Captain Calamity operated on the opposite coast simultaneously! This caper drew the attention of Robin and the remaining core membership of the Teen Titans, as well as the newly formed Teen Titans West. Only with their combined forces were they able to defeat Esper/Calamity, a defeat from which he never recovered as he retired from villainy.

Professor Gaunt returned one final time in 1945, now wearing the helmet  full-time which granted him further powers against his foes during a second clash with Sandman and Sandy. As seen in the America versus the Justice Society series, while Sandman was explaining during a congressional hearing the reason for his retirement due to a heart attack, an image of he and Gaunt was seen in battle. Evidently, the Professor’s helmet induced the heart attack upon his masked foe, as Gaunt obtained a measure of revenge against his foe.

Interestingly, this same cerebral device utilized by these Gotham villains was also developed and employed by Owlman, the counterpart of the Batmen of Earth-Three. He also used it for evil in his own Gotham City, before first Earth-One's Batman and later Earth-Two's Huntress defeated.