Is your character mean, nice, stupid? That can be determined all by their personality...
Most characters have three personalities. The first two mixed together to make their main personality, and the third one arising when danger is near, e. g. Character number one's main personality is a mix of harshness and intelligence, while in a dangerous situation he would be brave.
Sometimes there are a characters with four personality types, the first three being their main personality, and the fourth appearing what they face danger (the personalities could be split so that the third and fourth are displayed when danger arises).