Iron Fist #4 (1976)

As Iron Fist battles Radion, the radioactive being reaches critical mass causing an explosion. Watching the situation on television, Joy and Ward Meachum and their hired man Steel Serpent comment on the situation. Steel Serpent believes that Iron Fist had survived the explosion and hopes to kill him with his own hands. Steel Serpent's prediction rings true, Iron Fist does survive the explosion, however is at risk of dying of exposure to radiation, however with the spiritual goadings of Yu-Ti and his mother, Iron Fist uses his mystical might granted to him by Shou-Lao heals himself. Back on his feet he is startled by the activation of a video diary of Henri Sorel the scientist that became Radion. He explains how he came to become Radion and how he had constructed a device to cure himself. Iron Fist realized that Radion had come to cure himself when he had attacked. Tracking down the creature, Iron Fist battles Radion through the General Post Office Tower, tricking the unstable Radion into falling into his own machine and activating it, turning him back into Sorel once more. The repentant Sorel feels terribly about the death and destruction he wrought as Radion and passes out from exhaustion.