A megalomaniac is a pathological egotist, someone with a psychological disorder who exhibits symptoms like delusions of grandeur and an obsession with greatness, power or wealth.
A sociopath is a person whose behavior is antisocial, often criminally greedy, and who lacks a sense of moral responsibility, empathy or social conscience. Sociopaths never sincerely apologize nor are they capable of exhibiting remorse for wrongs that they have committed.
A narcissist is person who has an inflated sense of their own importance, a deep need for admiration, sexual gratification, applause and a lack of empathy for others.
A paranoid person or group exhibits excessive or irrational suspiciousness and distrustfulness of other individuals or groups.
A xenophobe is a person who is fearful or contemptuous of that which is foreign, especially of strangers or of people from different countries or cultures.
