Complex sentence: Later, Ellis claimed that the character was not in fact based on his father, but on Ellis himself, saying that all of his work came from a specific place of pain he was going through in his life during the writing of each of his books.
Split into simpler sentences: Later, Ellis claimed that the character was not in fact based on his father, but on Ellis himself. Saying that all of his work came from a specific place of pain he was going through in his life during the writing of each of his books.