Determined Daredevils of Dual Dimensions

Both Boston Brand and his counterpart the Firebrand, Rod Reilly, were prolific athletes demonstrating remarkable acrobatic prowess as well as superb fighting techniques. While Boston plied his trade as the featured acrobat for the Hills Circus, known by his professional name of Deadman, Rod was a bored rich playboy who adopted his Firebrand alias in order to battle crime. Although not a vigilante himself, Brand would likewise like Firebrand face the forces of evil.

Eventually, tragedy struck both men. Boston was struck dead by an assassins' bullet, Rod was nearly killed during the sneak attack by the Japanese Naval Fleet on Pearl Harbor. Despite this, each had siblings that carried on their costumed careers. Rod's sister Danette became the second Firebrand, while Boston's twin brother Cleveland became the second Deadman. While Danette would carry on as a superheroine like her brother, Cleveland kept to being a circus acrobat like his brother.

The legends of Boston and Rod carried on, with Firebrand having left his native Earth-Two for Earth-X. Rod was in pursuit of his arch-enemy the aspiring mystery man* turned New York City Nazi collaborator Silver Ghost (aka Raphael Van Zandt). Earth-X was also where the Freedom Fighters formerly of Earth-Two had migrated to years earlier. 

And Reilly would appear on Boston's Earth-One shortly after Brand seemingly perished, although Rod also seemingly died at the hands of his arch-foe the Silver Ghost. Despite this, Boston would reappear alive to team-ups with Batman, as would Rod alongside his Freedom Fighter allies, thanks to the machinations of Multiversal science.

During the Crisis on Infinite Earths recruited heroes from various points in time and space, and so among those assembled throughout the ages to save the Multiverse were the high-flying Boston Brand and his cosmic twin, Firebrand. Both heroes were adept at traversing dimensions, and both were the pinnacles of peak physical conditioning.

Interestingly, Silver Ghost’s secret origin was tied into his being inspired by earlier fictional mystery men. This plus motivational words from his father led Van Zandt into becoming a masked detective in 1939, until he encountered the Earth-Two Batman during his first case (as revealed in Detective Comics #1027). Presumably following this, Silver Ghost switched sides and affiliated himself with the German government with promises that one day they would reward him his presumed Van Zandt inheritance of Manhattan island, which he laid claim to from historical records.

As for Raphael's counterpart Cleveland, he too was inspired by his late twin which led to his inadvertently teaming up with the Batman in pursuing the organization behind the death of Boston, the League of Assassins. Together, Batman and Deadman were able to temporarily defeat the League, with its leader the sinister Sensei retreating until a later occasion when the old man sought vengeance on his foes.