Nightmare doesn’t trust anyone completely and he’s mostly afraid of dream he doesn’t sleep at night and he gets harassed by a lot of people a lot of the time. a lot of people think that he is a criminal because dream turned him into a criminal but he is a nice guy but he doesn’t believe everybody else would be able to see him the way that they were supposed to be is the guardian of the negative fruit and his big brother dream is the guardian of the positive fruit.