Complex sentence: Luthor then attempts to kill Fox, but Batman intervenes and reveals that he is the one who anonymously tipped the Wayne Enterprises' CEO, tells Luthor that Gotham is not for sale, and warns him to leave.
Split into simpler sentences: Luthor then attempts to kill Fox, but Batman intervenes and reveals that he is the one who anonymously tipped the Wayne Enterprises' CEO. He tells Luthor that Gotham is not for sale, and warns him to leave.