Henri Sorel was a research physicist with World Health and director of Project Damocles, an international effort to find a cure for radiation poisoning. When he was approached by goons working for Harold Meachum who offered him money in exchange for full rights to the cure, he refused and was severely beaten. He was knocked into radioactive isotopes and became an inhuman being capable of generating nuclear blasts, calling himself Radion.
Looking for help in controlling the radiation, he sought the assistance of the Puppet Master and helped him against in a fight pitting Thor against the Fantastic Four.
He next appeared in London, destroying an airplane coming in from the US that carried Iron Fist and Misty Knight as passengers, in an attempt to blackmail the British government into giving him nuclear materials he needed.
During a fight with Iron Fist, he was knocked into an anti-radiation transformer he had himself developed and was drained of his power. He returned to his human form and went on to work on Project: Pegasus under his civilian identity.