First the otherworldly heroes are being hypocritical, if you are going to destroy the world then what does it matter if someone else is "killing innocent people" as it is the same thing you are trying to do.
Second I hate when the person keeps talking shit instead of just acting. If you have all the chips why are you being provoked by someone? What does it matter what they are saying? If you are going to kill someone and you sure you can do it then just do it, there is no point in keeping her alive anyway. Point of this is that when this kind of thing happens shows that the author has no idea WTF they doing anymore and it makes the story shit.