high-and-mighty

1. offensively self-assured or given to exercising usually unwarranted power

    e.g. an autocratic person
           autocratic behavior
           a bossy way of ordering others around
           a rather aggressive and dominating character
           managed the employees in an aloof magisterial way
           a swaggering peremptory manner

    Synonym: autocratic bossy dominating magisterial peremptory