User blog comment:Magma MK-II/What makes a hero a villain?/@comment-1705775-20101105102722

a hero becomes a villain when they begin to cross the "Moral Event Horizon" - basically you can do a lot of nasty stuff and still be a hero but some things will make you fall from grace quickly.. For example a hero can rebel against authority and be heroic despite them verging on being anarchists or even terrorists (see "V" for example) - almost all superheroes are vigilantes yet are considered heroic. Yet if a rebel sets a bomb that kills a large number of civilians, especially unarmed, they have crossed the "Moral Event Horizon" and become evil in the eyes of all but a very select group of people. Likewise a superhero who tortures his enemies (such as Punisher) can never really be considered a hero as the act of torture is crossing the "Moral Event Horizon". Basically, if a hero does something that makes someone think "that was just plain nasty/uncalled for" they've likely become a villain.