37 years ago - Daniel Patrick Cassidy is born.
26 years ago - 11-year-old Dan begins studying martial arts.
20 years ago - 17-year-old Dan wins a national martial arts title.
15 years ago - 22-year-old Dan gets his first movie stunt work.
10 years ago - 27-year-old Dan, made up as the title character for a movie based on the Blue Devil, an old Gypsy Legend, is attacked by the demon Nimbos, who was summoned by a small clan of Gypsies that had intended a simple curse on the set. Nimbos mistakes Dan for a treasonous underling, and curses him to permanently take the form of the Blue Devil.
7 years ago - 30-year-old Dan watches Eddie Bloomberg die in a car accident. he returns as Kid Devil.
6 years ago - 31-year-old Dan makes his way to hell to free Eddie Bloomberg's soul after his death. He deals with Etrigan, agrees to become a full demon in service to him if he will battle Nimbos to release Eddie's soul to heaven.
4 years ago - 33-year-old Dan deals with heaven to free his soul from damnation. with the help of Zatanna & Jim Rook he journeys back to hell to free an angel, & gains Lucifer's trident.
1 year ago - 36-year-old Dan participates in the 5th Shadowpact, forging the spells that allowed Maggeddon to manifest in our reality where he can be stopped by the collected heroes of Earth. With her team disbanded, he joins the newly-formed Justice League Task Force.
Blue Devil was part of a early 80's push of new characters. In his case, it was very clearly an attempt to make a book that was rooted in humor, which is a bit of a throwback idea. The book was moderately successful, but it didn't really stick. The character came back as a part of the Shadowpact as more of a brawler.
The original concept was centered on the fact that he was a stuntman trapped in a robotic suit that LOOKED like a devil. Basically, he was Iron Man. By my estimation, that conceit was really hampered by the fact that it makes no sense. Why is he wearing a suit so powerful he can use it to fight crime when all he was doing with it was movie stunt work? Just looking at the character's design, there's nothing about him that suggests that he has anything technological about him. Later takes on the character acknowledged this, making him an actual demon, but they still had to deal with the fact that his origins skewed so hard out of wack.
We've addressed this by using virtually the same story, but making him an earthbound demon from the very beginning. Having him interact with Etrigan and clearly defining which lords of hell he is bound to solidify that story, and creates narrative elements which immediate payoff, requiring him to quest to alter his destiny. He becomes a character much easier to follow.