Complex sentence: Screenwriter David S. Goyer explained in "Premiere" magazine that he planned to use the Joker as the main villain for the sequel, "The Dark Knight"; the character was portrayed by Heath Ledger.
Split into simpler sentences: Screenwriter David S. Goyer explained in "Premiere" magazine that he planned to use the Joker as the main villain for the sequel. In "The Dark Knight" (2008) the character was portrayed by Heath Ledger.