Daniel Patrick Cassidy was a stuntman and special effects artist who was starring in the movie, Blue Devil. He created a costume with an exoskeleton and special effects devices for the movie, but when two of his costars unintentionally freed the demon Nebiros, he used the suit for a real life application. He fought the demon and sent it back to Hell, but not before Nebiros hit him with a blast of mystical energy, grafting the Blue Devil costume to Cassidy’s body.

As a hero, he became superstrong, a master hand to hand fighter, and had enhanced senses, then later he gained the ability to find demons that are on Earth and send them back to Hell, and wielded the Trident of Lucifer. Created by Dan Mishkin, Gary Cohn, and Paris Cullins, he debuted 40 years ago in Fury of Firestorm #24 (June 1984).

Cassidy responds rather positively to the drastic change in his physiology by fighting villains and eventually becoming the superhero, Blue Devil. He joined the Justice League and took on his former assistant Eddie Bloomberg as his sidekick, Kid Devil.

Unfortunately, Blue Devil was enjoying fame and adulation a little too much. Recognizing an opportunity, the demon Neron offered to make Cassidy a famous actor if he destroyed an electrical substation in the desert. Since no one was working there, Blue Devil figured it wouldn’t be a big deal, so he completed the task. It was not as harmless as he expected, and Eddie’s aunt was inadvertently killed when the power outage caused a crash.

Blue Devil rebelled against his new relationship with Neron by trying to stop the demon’s plans, but he died in the process. He was resurrected, except now he was a real devil instead of a man in a suit. Blue Devil rejoined the Justice League, but was killed again when Mist sprayed him with holy water. After he was resurrected for the second time, Blue Devil confronted Nebiros and was able to take his trident that was powered by magic from Lucifer, and Firestorm was able to finish off Nebiros.

Then Blue Devil joined the Sentinels of Magic and sacrificed himself to stop Hermes Trismegistus. He returned to life once again and was sent back to Earth, armed with Lucifer’s Trident to capture demons and send them back to Hell.