Darkseid's Version of Kryptonite Is Even Deadlier Than Superman's

screenrant.com:

While Superman is famously vulnerable to kryptonite, even that radioactive material doesn't have anything on the New Gods' radion — a substance that can even kill Darkseid. Created by Jack Kirby, the unknown mineral has been a signature weakness to the people of New Genesis and Apokolips, especially during the events of DC’s Final Crisis. Having shot a radion bullet through time to kill his son Orion, Darkseid gets a taste of his own medicine when confronted by Batman, who shoots him with the same bullet. The moment confirmed that while longterm exposure to kryptonite can prove fatal to Kryptonians, only a small fragment of radion is enough to kill any number of the New Gods.

Introduced in Kirby’s Forever People #1, Darkseid briefly left a hero, Beautiful Dreamer of New Genesis, hooked up to a trap consisting of bombs full of radion, an element that is a grave concern to the New Gods. Fortunately, Superman uses his superspeed and flight to remove Beautiful Dreamer and the others far enough from the bombs’ explosions to have no effect on them. Since then, radion has become established as something that few New Gods have survived exposure to, except in cases where advanced technology like the fabled Mother Box has protected them from certain death.

RELATED: Superman's New Weakness Is Cooler Than Kryptonite (And Here to Stay)

In Final Crisis by Grant Morrison, J.G. Jones, Carlos Pacheco, Marco Rudy, and Doug Mahnke, Earth’s heroes discover the body of Darkseid’s son Orion, killed by a radion bullet that had been sent traveling back through time from the future. As things continue to worsen, Wally West and Jay Garrick witness Barry Allen, who had previously died in 1985’s Crisis on Infinite Earths, trying in vain to catch