Original Speed Demon
Jay Garrick (An Amalgam of Marvels Phantom Rider and DC's Golden Age Flash) was the first Speed Demon, Jay was forced to be bound to a demon called Etrigan. Jay in his old age did everything he could against his mortal enemy, Night Spectre but he was no match and just before Night Spectre could deliver the final blow Etrigan abandons Jay, Jay without the power of Etrigan turns back to his weak human form, Night Spectre kills Jay and captures his soul.
The Second Speed Demon
Blaze Allen [Marvels Johnny Blaze and DC Barry Allen] is a stunt rider in Quentin carnival and in his spare time an amateur mystic.
One night after his motorcycle act, Blaze is approached by Night Spectre. Night Spectre demands Blaze for his soul but Blaze escapes on his bike, Night Spectre just laughs and disappears, never to be seen again...at least that's what they thought.
Blaze eventually marries the love of his life Iris Simpson. However a short time after the couple are married Night Spectre appears again and drains Iris of her life force and steals her soul. This sends Blaze into a deep depression and starts to obsess over his magic.
One day Blaze is contacted by the wizard Merlin who tells Blaze of a demon called Etrigan [the same demon who was bonded to Jay Garrick] who had a long standing hatred of Night Spectre and was probably the only demon strong enough to defeat Night Spectre. Merlin told Blaze how to summon the demon, Blaze had to chant “Gone, gone from the man, arise the demon Etrigan”.
Etrigan appeared to Blaze and asked Blaze why he had summoned him, Blaze explained about Night Spectre and how he wanted revenge, Etrigan was impressed by Blazes attitude and bonded with him. Blaze became the second Speed Demon.
Enter Kid Demon
Wally West [Marvels Daniel Ketch and DC Wally West] is the teenage nephew of Blaze Allen [Speed Demon] who Wally sees as a father figure. After witnessing one of his uncle’s battles, Wally decides to help his uncle. Wally finds a way to contact Merlin, Wally asks Merlin to make him like his uncle, Merlin summons an unraveled demon and bonds it to Wally. Wally takes the name Kid Demon and uses a flaming Motorbike instead of running.
Much to Blaze's dismay he lets Wally help in his fight against Night Spectre. The two have a long fight with Night Spectre and win, they destroy Night Spectre and free all the souls he had collected over the years, two of the souls where Jay Garrick [the first Speed Demon] and Iris Sampson. After the fight Blaze is worried about Wally and his new found powers and where he got them from. Blaze and Wally now travel around the world fighting demons and criminals alike.