Complex sentence: He is the most prominent fictional character in the early books of Herbert's "Dune" science fiction series; he takes the Fremen name Paul Muad'Dib and the Sietch name Usul.
Split into simpler sentences: He is the most prominent fictional character in the early books of Herbert's "Dune" science fiction series. He took the Fremen name Paul Muad'Dib and the Sietch name Usul.