Johnny Mann was a scrawny but courageous reporter for an international news syndicate who had lost a leg while serving during the Korean War. While covering a bloody civil war on the Mediterranean island of Cyprete, he complained aloud while standing in the ruins of an ancient temple that the gods play with men's lives while leaving them defenseless against the forces of war and crime. Taking offense, the Roman gods transported him to Mount Olympus where he was put on trial before Jupiter, all-powerful king of the gods, for his impudence. The war god Mars argued for his immediate destruction, but Vulcan, lame-legged god of fire and forge, spoke up in his defense, and Venus, Goddess of love agreed with Vulcan. In the end, bonding with the orphaned newsman over their similar disabilities, Vulcan agreed to adopt Johnny and share with him god-like powers that would help him fight injustice in the mortal world.
By calling on Vulcan's aid, Johnny would transform into a superhuman demigod, whole again and mightily muscled and clad in indestructible Roman-style armor and shield with the power to summon both fire and powerful ancient weapons from his adopted father's forge. However, it was the judgment of Jupiter that his powers could be removed from him at any time if the gods ever decided he was unworthy of them. Mars often plots against him to make him lose favor with Jupiter or destroy him and was exiled from Olympus for this.
Indestructible armor that enable the Son of Vulcan to cast fireballs and summon powerful ancient weapons from the forge of his adopted father Vulcan.
- This version of Jonathan Mann (Earth-Four), including all history and corresponding appearances, was initially erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. However the ending of Convergence retroactively prevented that collapse, saving all the alternate realities, though in an "evolved" form. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 8 Appearances of Jonathan Mann (Earth-Four)
- 2 Images featuring Jonathan Mann (Earth-Four)
- Quotations by or about Jonathan Mann (Earth-Four)
- Character Gallery: Jonathan Mann (Earth-Four)