Complex sentence: The strongest difference between the two works lies in the primary character: the film's Dixon Steele is a screenwriter with an offbeat lifestyle, and a decent person with fatally poor impulse control and prone to wild overreaction when enraged.
Split into simpler sentences: The strongest difference between the two works lies in the primary character. The film's Dixon Steele is a screenwriter with an offbeat lifestyle, and a basically decent man prone to wild overreaction when enraged.