If you say that someone is ~, you are emphasizing that they use their power over other people in a very unfair or cruel way.
The country was ruled by a ~ tyrant.
= tyrannical
ADJ emphasis
If you say that someone is ~, you are emphasizing that they use their power over other people in a very unfair or cruel way.
The country was ruled by a ~ tyrant.
= tyrannical
ADJ emphasis
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012