Complex sentence: Confused, Sinestro demands to know what they want from him, but the Guardians simply respond that they want from him what they want from all Green Lanterns, for him to protect his sector.
Split into simpler sentences: Confused, Sinestro demands to know what they want from him. The Guardians simply respond that they want from him what they want from all Green Lanterns, for him to protect his sector.