-Once again: the overarching theme for Superman's rogue galleries should be Enemies of Humanity Today, versus the Man of Tomorrow.
-Most of these guys have obvious strength, durability, and flight or power armor and genius intelligence, I'll try to note differences between them to give them some variety within these obvious stock powers to tango with Superman - and they SHOULD, Superman INVENTED the action-packed superhero strip, it's literally in the name of his debut comics and old nickname of "the Action Ace".
-Most of these guys need motivation besides "'hate Superman." I mean they do! If they kill him they'll be overjoyed! But they'll then continue their motivation, rampages, or greed ANYWAYS. They need a reason to be villains and continuing reason why Superman in specific is the guy able to continuously stop them.
-Clark, Kara, and Zod should be the only surviving Kryptonians, and I like both the idea of Supes being the strongest between them both naturally (farmboy strength, yo) but from all that yellow sunlight as well. So much endless crap from Krypton keeps coming in when Clark should be focusing on cool stuff in the present day and in today's world.
-I do like Zod knowing all the Silver/Bronze Age Kryptonian martial arts they made up as a fun reference, I imagine him versus Clark equivalent to a Cody Travers vs Rolento fight in Street Fighter (Alpha 3 is your best bet), with Zod flipping all around thanks to his newfound powers in conjunction with his training ,and Clark equivalent to a boxer/farmboy brawler in turn but much more in tune with yellow sun-granted powers like flying, laser eyes, etc. Zod's here to Make Earth Krypton Again and collects idiot Earthmen to supplement whatever Phantom Zone criminals (preferably none) as his troops. Make him represent totalitarianism and militarism at its worst.
-Brainiac should have no connection to Krypton or was their supercomputer or whatever. He can collect Kandor if it's an appropriate timeline but that's about it. He should've started off as a biological alien that wanted to know everything and through endless re-cloning, uploading his mind endlessly into AI, etc. became as soulless as expected and his motivation to ending or encapsulating all life so he will know everything, forever, in perfect unchanging order. Superman is the first guy able to stop him, and the first to make him feel emotion that he hasn't in eons... incidentally, he's the Ra's al-Ghul of Superman and demands longer-form, high-concept stories by default. Let his main power besides "genius" being tentacles of sorts, be they biological or tech like Doc Ock's to supplement whatever super strength he's engineered for himself.
-Lex as I said in posts earlier in this thread and others should be DC's Dr. Doom equivalent. THE villain versus THE hero. Dude should be able to do anything and have it make sense under his guise of leading humanity into a true golden age at the cost of its soul. CEO as his startpoint, becomes the mad criminal scientist on the run ever after, but could casually pull through legal loopholes to take back Lexcorp whenever the writer wants him there for a bit. It's Lex, he just knows how to do shit like that. His main power besides "genius" should be the power armor suit. Toyman may be the better engineer, Metallo's metal body stronger than his armor, Brainiac a better biologist, but.... he is not only second place to each but can do all of that versus their specialties alone.
-Metallo should be the one thing consistently stronger than Supes but oddly self-aware he's continuously defeated. But he's a pure sadist. His stories should be about how much he's gonna get away with before Superman kicks his ass. He can't feel anything, so all the pleasure he gets is from wrecking shit. Yanno Cain from Robocop 2? Yeah. He's simply sadism made, ah, metal.
-Toyman's the best engineer in the DCU but grew up so rejected and dejected he's basically an incel and leading the 4chan beta revolution - dude simply cannot move on, he's rejection's consequences made flesh. In spite of his ability to make billions with his engineering hyper-genius, that pain is ingrained in him so much he'd rather burn down Metropolis in revenge anyways. And he's a manchild. Less toy biplanes or wooden puppets and a lot more sleek miniature fighter jets and creepy metallic little robot men, looks like the fat chud in an army outfit than the thin court jester.
-Silver Banshee should just represent the worst of cultism and growing up with shitty beliefs. Not much else to say there. Keep her on the more evil side by making her truly believe her beliefs are correct and must be implemented on society.
-Atomic Skull should be the version that got kicked out of STAR Labs. Has a wilting death aura around him and throw out radioactive blasts from experimentation gone wrong. Dude literally will do anything to continue his scientific work - four eyes, no soul. Represents science at all costs with zero ethics.
-Parasite should be greed. Dude knows he could die anytime, anywhere, and will whore himself out to gangs or go get something he wants since he can kill people for a burst of life. Literally gives no shits on anyone but himself. Naturally better specimens like healthy humans or Superman is best, but he's simply out to live it up much as he can. Selfish asshole.
-Livewire's just out there to cause chaos. What a bitch! Strong enough in electrokinesis to jolt Superman, of course.
-Manchester Black is nihilism. Powerful enough telekinesis to be a worthwhile match to Superman. Seriously, lean in on that nihilism and cynicism more. Have him just wrecking shit claiming nothing matters. Not even in a self-centered way like Parasite or Livewire, dude just wants to tear it all down like a brat.
-Doomsday should just represent how brutal nature is or something. Always evolving, acts like a wild animals, just a force of nature.
-Conduit has a death aura like I read he has and has it out for Clark to where he could be Batman and he'd not care he just wants Clark dead, Luminous has hard light constructs and is a selfish twat who's self-pitying into a life of crime when his obsession with Lois goes south, and Prankster per Kurt Busiek is great as a Krusty the Klown equivalent who goes into crime for attention and whores himself out to others for distraction. Just petty jerks, even if you have jealousy (Conduit), obsession (Luminous), and attention-whoring (Prankster) as their specific bits.
-The majority of the above, even ones like Zod or Toyman or Atomic Skull, should have gangs or henchmen scooped up to help distract Supes or achieve their specific story goal. They mostly control organized crime by now in Metropolis. The remaining "normal/human" gangsters and criminals merge into a singular large Intergang under Bruno Mannheim when you wanna do some old-school investigative criminal stories with Clark Kent, reporter.