Definitions of magisterial:

• adjective:   of or relating to a magistrate

  Example: "Official magisterial functions"

• adjective:   used of a person's appearance or behavior; befitting an eminent person

  Example: "She reigned in magisterial beauty"

• adjective:   offensively self-assured or given to exercising usually unwarranted power

  Example: "Managed the employees in an aloof magisterial way"