Complex sentence: It intensified Batman's feud with the Joker, making it even more personal: in the course of the' story arc, Batman is exposed to the Scarecrow's fear toxin, causing him to hallucinate Jason's death.
Split into simpler sentences: It intensified Batman's feud with the Joker, making it even more personal. In the course of the' story arc, Batman is exposed to the Scarecrow's fear toxin, causing him to hallucinate about Jason's death.