Kromium

Kromium is a fictional element appearing in DC Comics, primarily associated with the villainous character Metallo. It is depicted as a rare, radioactive, and incredibly potent mineral with unusual physical and chemical properties. In the comics, Kromium is often mined from extraterrestrial sources or found in deep geological formations. Its most significant characteristic is its ability to drain energy, particularly life force and superpowers, from organic beings and even technological devices.

When bonded to living tissue, Kromium can induce rapid aging, weakness, and eventually death. This energy-draining property is the primary reason for its use by Metallo, whose cyborg body is powered by a Kryptonite heart that also contains Kromium. This allows Metallo to not only be a physical threat but also to weaken Superman by proximity, drawing on his solar energy. The exact scientific principles behind Kromium's energy absorption are not elaborated upon, serving more as a narrative device to create powerful antagonists and introduce unique challenges for heroes. Its origins and precise composition remain largely a mystery within the DC Universe, allowing for flexibility in storytelling.