Complex sentence: Since then, the rebellion has been led by one of his brothers, Abdul-Malik al-Houthi, while his father, Badr Eddin al-Houthi, became the group's spiritual leader.
Split into simpler sentences: Since then, the rebellion has been led by one of his brothers, Abdul-Malik al-Houthi. His father, Badr Eddin al-Houthi, took over the position as the group's spiritual leader.