While most people might think that the Joker is a purely evil character, I honestly believe he isn’t only a complex character, but also someone who deeply wants to be a hero. Lots of comic-book villains are complex characters with deep motivations and reasons for their worldviews. There are also many comic characters who are simply evil and want to cause death for the sake of it. But what if the Joker isn’t like that at all?

https://screenrant.com/joker-wants-to-be-a-hero-theory-evidence-explained/