Jesus dude, you on a mission?
Yes, it’s just what’s the hardest piece you have played. What’s personally challenged you the most. It’s not for any research purpose or any public comparison and it’s perfectly acceptable to have a subjective opinion.
Whereas what’s the hardest Liszt piece is never going to have an answer and has been asked 1000 times, like most of your recent posts.
Plus someone has already made a what’s the hardest list…(in their opinion)