The New Gods are vulnerable to a substance called Radion.
Its source is unknown and its effects are toxic only in sustained amounts or after explosive exposure. The average New God can be slain by an application of Radion from a Radion blaster or bomb. More advanced beings such as Metron, protected by their Mother Box, armor and sheer toughness, have been known to take two hits and survive.
The first appearance of a material called Radion was in The Atom #23, in the form of a ball of radioactive matter made by Nuclear Laboratories Inc; designed to be used in the atomic motors of future spacecraft. It was not known if the two Radions were the same material, though it was unlikely as the Fourth World Radion was a divine material.
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