Black Kryptonite
Black Kryptonite is said to have negative mental effects on Kryptonians, the effects have varied from; becoming evil, split personalities and the splitting of a good and bad persona into two entities.
Name:
Black Kryptonite
Aliases:
Start year:
2006
First issue:
Lex Luthor first used this on Supergirl (having received it from Darkseid).
