Zatvor is a rare, difficult to obtain mineral and therefore very expensive.
This rare material is mined on planet X and then exported to the rest of the universe. It is highly regarded for its properties. Zatvor is used in genetic engineering, nanotechnology, synthetic biology, and robotics
It is often used to make various prostheses, which involve working in symbiosis with the biological body. But direct use on living things most often leads to the inevitable death of the wearer. Rumor has it Bayons experiment with Zatvor on living beings in secret laboratories(what is illegal).
It is believed that Zatvor simultaneously maintains life, and at the same time kills the wearer.