Who is Mojtaba Khamenei, the new supreme leader of Iran?

In ideological terms, Kasra Aarabi, director of IRGC research at United Against Nuclear Iran, has described Mojtaba as "like his father - only on steroids". Having joined the Islamic Revolutionary Guard Corps (IRGC), the notorious paramilitary group responsible for enforcing Islamic rule under the regime, at 17, he fought in the Habib bin Muzahir Battalion.