I think that what makes a good and evil person is the greater good. If a person does morally bad things, but is the greater good then to me that is a good person. I just think that what makes a good person (and a hero too) is someone who is willing to do what has to be done but no one wants/cant do. Since u brought up Batman the Dark Knight...
****SPOILERS!!!*****
At the end, when Batman decides to take the blame for Harvey's murders so that Gotham City would still have the image of Harvey as their saviour, their "white knight", that was very heroic in my eyes. Any other person could have just done nothing and let Gotham City to rot because the only "good" person ended up doing what he was trying to stop so there would be nobody for the citizens to look up to. Also, like I said earlier, that decision that Batman made, benefited the majority and he gained nothing from it, in my eyes, that is what makes a person good.
****SPOILERS!!!****
