Probably the only upside to cancelled shows is that fanfiction attempts to fill in the holes they leave behind, and Young Justice had a lot of holes in it. Very obviously the show was designed to run for a least a few more seasons to explain everything and justify the numerous characters it introduced.
One such character was the Riddler; I was never sure how I felt about his introduction into the series. We first meet him while as an inmate at Belle Reeve, not Arkham, and instead of working on his own personal goals—like proving himself smarter than Batman—he’s an agent for the Light. I was a little underwhelmed by his character, and I felt as if the show should have done more with him, instead of having him be a random adversary for our heroes, especially since working with the Light never seemed to line up with his original goals in the comics. I just wanted something to justify his alliance with them. And Enough by FelineOverlord doesn’t set out to do that specifically, but it does give me some closure with his character.