Mon El is my favorite Zoner by far.
My issue is the Zoners save for Mon-El and Zod are pretty much interchangeable to me. It's all hardened prison nutjobs and Zod. Faora/Ursa could have been a good Supergirl rogue, but she isn't even that as far as I know.
I guess the idea of a Kryptonian serial killer is interesting at least. I assume that's what the mummy guy's deal was,
Considering what modern takes on Krypton are like I'm surprised there aren't any Political Prisoners in the Zone. As far as I know, Mon El is the only guy that got put in the Zone for medical reasons. You'd figure he might not have been the only terminal case that got put in the Zone.
The zone has more potential to be interesting if it were something more than Krypton's Alcatraz.