Mohammad bin Salman (full name Mohammed bin Salman bin Abdulaziz Al Saud) is the Crown Prince of Saudi Arabia, and the heir apparent to his father, King Salman, though many consider him to be actually manipulating his father and be the true power in the kingdom of Saudi Arabia.
Though he is responsible for a number of political reforms in Saudi Arabia - including increasing rights for women in the country and a reorganization of the Saudi economy - he is also responsible for torture of political opponents and is also accused of warmongering as part of Saudi Arabia's ongoing conflict in Yemen.
He is responsible for the brutal killing of Saudi dissident and journalist Jamal Khashoggi, allegedly to silence him because of his extremely vocal criticism of his government.