Pang - The Greater Good
A good guy, his ethics is utilitarianism. It is right to kill 4000 men in order to save many thousands.
Er Hu - The Hero
Also a good guy, he believes that there are imperatives that cannot be compromised. The 4000 men cannot be killed, regardless of the implications.
Wu Yang - Follow the Leader
Yet another good guy, his ethics is borrowed. Lacking his own, as a result, he eventually makes some tragic choices.
Pang had morals based on his own reasoning. Dependent on his situation, his ethics was flexible. What was wrong in one situation might be undesirable but necessary in another. Wu Yang was loyal and faithful, believing and following Pang. When Pang stumbled him, he was lost without a source of ethics. Finally forced to make his own moral judgment, he did so badly.
Er Hu, a former bandit, was inspired by Pang's utopian vision. Reformed, he chose to be a hero. His ethics were not dependent on the situation and are consistent. The right thing had to be done regardless of consequences to himself or anything else for that matter. Blameless to the very end.
