Green Kryptonite (Earth-99)

Kryptonite is a radioactive mineral originated from Krypton.

History
At some point, Krypton was destroyed and Kryptonite was scattered on Earth.

Later, Bruce Wayne acquired pieces of Kryptonite and used it against Superman, eventually killing him. The same piece was then installed on his exoskeleton after injuries in the fight and was used against Supergirl during the Crisis.

Kate Kane then took the piece along with her and informed Kara that she acquired the piece, only to be forgiven and told to keep in case of emergencies.

After the Crisis, the piece eventually ended on Earth-Prime and Kate Kane informed Bat Team that the piece would be the final one in Gotham City. She then traveled to National City asking Kara if she could destroy the piece as it is a critical weakness for the Batsuit, the plane was only to be blown up midair and the piece was taken by "Bruce Wayne" against the new Batwoman. During the fight, "Bruce" shot "Batwoman" with the piece and caused an injury on Ryan's shoulder position, weakening her ability to fight.

Functions

 * Kryptonian weakening: When exposed to Kryptonite, the green mineral makes Kryptonians vulnerable and causes dizziness.
 * Batsuit penetration: The Batsuit is vulnerable to the green mineral and will be easily breaking apart with Kryptonite when carved into weapons.
 * Radiation: When penetrated into human body, Kryptonite mixes with blood and affects the victim's physical conditions.