Time for some trolling. xD
Definitely doing that for Harry Potter books lol, fuck that author (she who shall not be named).
Best let them come up with the idea, then you publish it the next day, and watch the author’s reaction:
“Someone has already published a book on the same idea? Nooo wayyy!”
[Insert “U Mad Bro” Trollface Meme]
Regarding She-who-must-not-be-named, somebody already kinda tried it, it didn’t work because the fomrer was already in possession of large sums of money by that time (and the challenge was kind of spurious anyway) and then everyone forgot about it.