Fan Casting This Is Your Brain on Evil in Sort by Tropes

Congratulations, This Is Your Brain On Evil. Since evil is often depicted as being a tantalizing and corrupting influence, it's just as often used as a euphemism for another, similarly tantalizing and corrupting, influence: drugs. Just like drugs, the side effects are all there: addiction, withdrawal, uncontrollable behavior, and, eventually, health problems and death. Usually, when a character is thrust into this trope, they get into it only knowing or caring about the positive, "feel-good" parts of the power or evil they're taking and never seem to realize that they can't take the "good" parts out of the deal without acquiring the negative as well until it's almost too late.