to all the people here, calm down a bit, I'm with you on the point that there are situations in these comics were taking lives would be quite justified - the big always existing problem is: where is the line? sure, killing a maniac who just kills for fun seems okay, but what about a soldier who killed for his country? would be killing him still okay (if he falls on the battlefield, can't be helped, but I'm talking about straight murdering him since let's say he sniped the brother of our hero who maybe was just with a group of soldiers) a hungry orphan who kills for the sake of obtaining food - is he a villain since his victim was a normal human? or is it justified since otherwise he would have died? is it okay to sacrifice one human to save a thousand from certain death? which crimes justify a death sentence? and be aware that while we readers often know certain the villains since we "saw" them, the hero quite often don't, sure there is evidence, clues, the testifying of other but like in real life all of it could be false or at least manipulated (sure, here he saw his stepbrother shooting at him,) but quite often that's not the case, why do you think some kind of anti-lie magic, technic is used? to gice the good guys the absolute justification for punishment
sorry for the long text, but I hate it when people say: let us just kill all villains - whether in comics or real life