How did the joker become batman s arch nemesis?

{"top_answer":"The provided sources do not contain information on how the Joker became Batman’s arch‑nemesis.","long_answer":"The only verified source about the Joker is the 2019 film directed by Todd Phillips, which presents an alternative origin story for the character but does not address his relationship with Batman or how he became the hero’s arch‑nemesis. Consequently, based on the supplied evidence, there is no documented explanation for that development in the material available.","category_slug":"movie-facts","tags":["joker","batman","arch-nemesis"],"related_questions":["What is the origin of the Joker?","How did the Joker become Batman’s arch‑nemesis?","What is the relationship between the Joker and Batman?","Where does the Joker appear in Batman comics?","How did the Joker’s character evolve in comics?","What are the Joker’s motivations?","Who created the Joker character?","What is the Joker’s backstory?","What is the Joker’s role in Batman’s mythology?","What are key differences between comic and film Joker?"]}