I just read issue 50 of Judd Winick's Green Arrow which guest stars the Riddler. Not to spoil too much but the premise is that Roy Harper gets kidnapped by The Riddler and Green Arrow and the Outsiders have to bust him out of the Riddler's secret fortress (which we never heard about before and is never seen again)
But for some weird reason, the Riddler isn't wearing his usual green boiler hat and suit, but a skin-tight black tights with a question mark around his neck! Even worse the heroes don't even defeat him, the Riddler just... walks off. I thought maybe the Arrow family fights him in the next issue, but apparently The Riddler doesn't show up to fight Green Arrow again. What?!
It took me half an hour to search the internet for context, but fortunately CBR did an article explaining the Riddler's status quo at the time:
https://www.cbr.com/riddler-most-forgettable-makeover/
As someone who's actually really enjoying his Green Arrow run, I'll have to ask Winick what was the story behind this issue if I ever see him in person.