The identity of Fireball is associated to a DC character who is an analog to Marvel's Human Torch. The first iteration of Fireball was an analog to the Invaders' Human Torch (the Golden Age version, Jim Hammond) meanwhile the second (and third) version was an analog to Fantastic Four's Johnny Storm, the most popular and known Torch.
The original Fireball was once a comic book fan before being transformed into a hero by who they believe to be the Americommando. He was a member of the Crusaders. He clashed against Uncle Sam and the Freedom Fighters before being revealed than the Americommando was an undercover nazi criminal called the Silver Ghost. When he and his Crusaders teammates discovered the truth they allied with the Freedom Fighters to stop the criminal. Same as his friends he abandoned his hero identity after the adventure ended with his artificially acquired powers seemingly faded soon afterward.
Future Family's Fireball
The second Fireball was a member of the Future Family of Earth 7. He was destroyed along with his teammates when the Gentry attacked his world, with his body distorted into a massive living fireball, transformed in the dying sun of that world.
The third Fireball was a member of the Future Family of earth 8. He tried to stop Lord Havok from make the use of the Celestial Egg to being hatched but neither him nor Golem were enough to stop Havok from opening the door for an attack of the Gentry in his world, but with the help of several heroes from other parallel earths, the attack was repelled.