What do you think of Mongul? Is it better to first meet him as a Death Star thief (as in pre-Crisis comics and the Young Justice cartoon) or as an overseer of gladiatorial combat (post-Crisis and the Justice League cartoon)? Personally, I'm fond of the former, mainly because a reprint of DC Comics Presents #27-29 in the 1983 UK Superman annual was the very first superhero comic I ever read.
Mongul kinda sucks? He’s a rip off of a rip off who actually exists in the universe of the source material, bleeding everything cool out of Darkseid and then Thanos until you just have a big lunk left who hits stuff and proclaims his own greatness, but much like Doomsday before him he was in a Big Superman Story so he has to stay important forever. Plus he’s a space pirate but he doesn’t even wear a silly hat, which is just inexcusable.
Especially given they already fought in his most prominent appearance, maybe he should migrate into being a Wonder Woman villain. I think he’d serve as a nice villainous contrast, a super-strong monster ruling a sci-fi death sphere by dint of raw strength and thievery as opposed to a mythical island of enlightened warrior philosophers, the living embodiment of the war economy that allows him to justify atrocities in perpetuity. That, I think, could dig a little thematic significance out of him. And I would give him a pirate hat.