FranzOren wrote:
It's not a real psychology and it's not from real life.
The word "erotomania" has the word "erotic" embedded in it. So you can tell that the word has something to do with sexuality. If you're a regular dude in Bumfuck Michigan, and you imagine that Princess Kate has a crush on you, and longs to leave that Prince guy for you, then you may well have "erotomania".
Conceivably Joker could be homosexual, and could be deluded into thinking that Batman has a gay crush on him. But I dont think that that is what you mean.
Joker sees himself has being locked into a vendetta with Batman. Or something like that. Havent seen the movie. Just the Sixties TV show. So it wouldnt be a romance based relationship (delusional, or real)that he has, or imagines that he has, with Batman. So it would be something other than "erotomania".