Other forms: nihilists
If you reject all moral beliefs and take the view that life has no meaning, you could be called a nihilist.
Someone who is a nihilist is a believer of nihilism which literally means "nothingism." They believe in nothing, maintaining that life has no meaning and rejecting all moral and religious values as well as political and social institutions. A movie in which human beings are shown as fundamentally evil creatures doomed to fail might be said to have nihilist themes.