You can have your code of ethics about killing people, I can understand it! But will you let someone kill you to protect your ethics? You think people who depend on you will appreciate it while mourning your death? What about the people who will get hurt or die because you blindly follow your code? When your, or your friends, or innocent life are in danger, it's OK to go all out even if your opponent die! You still have your ethics AND your friends are alive!