Discuss Injun Joe as an epitome of evil.

You could argue he's the epitome of evil because of how willfully aggressive he is in pursuing evil ends. That he is a murderer and unpleasant fellow doesn't make him the epitome of evil, but the fact that he turns his aggression onto anyone he thinks has wronged him, especially when "wronging" him means doing good and trying to suppress or punish his own evil actions, makes him an unequivocally evil guy.