why am I attracted to mentally insane characters (black flags)?

i am very much intrigued and attracted to black flags, characters who are irredeemable psychotic beings. when i say black flags, i dont mean rapists exclusively. not rapists. but people who are just so clinically insane that their moral compass is broken and skewed or simply doesn't exist. which makes them borderline uninterested in romance sometimes.
eg. dan from brutal satsujin, oh inseop from for your murder, amy dunne from gone girl, sukuna from jujutsu kaisen.
and the thing is, their attractiveness is extreme to me BECAUSE they're insane. the moment they become "human", i lose interest. why is it so?