Slightly off topic; but this is one thing I overall respect the Spider-Man films for; they almost never reuse his villians. Raimi Trilogy: Norman Osborn/Green Goblin, Doc Ock, Sandman, Venom, Harry Osborn/Green Goblin, Amazing Duology; Lizard, Electro, Rhino, and yeah trying to set up all the others. MCU: Vulture, Shocker, Mysterio, The not-quite Sinister Six via bringing back the main villians from each non-MCU movie.
Where as Batman we got: Joker, Penguin and Catwoman, Riddler and Two-Face, Poison Ivy, Mr. Freeze, and Bane; Ra's Al Ghoul and Scarecrow... then Joker and Two-Face then Bane and Catwoman, then Superman and Lex Luthor, not gonna count JL as a Batman movie, and now we got Riddler, Penguin, Catwoman, Carmine Falcone, Joker, and maybe hints of the Court of Owls.
Batman keeps going back to same handful of villians. It's part of why I'm annoyed that this version of Riddler was more Anarky; a more obscure but still highly popular Batman Character. And it seems like we're likely going back to fully into the Joker well with the sequel, unless they take time really building him up. I'd love to see other Batman characters got spotlight for once. Mad Hatter, Firefly, Azrael, Hush, Clayface (like you don't even have to make him a monstrosity, just keep the shapeshifter or disguise aspect of him and he'd be perfect for this universe), Man-Bat, to name a few.
Of course there's a few revisits I wouldn't mind; a Scarecrow that's actually commits to being a villian and not just a somewhat forgettable background character, A Mr. Freeze and Poison Ivy that's not a joke. A Bane that actually shows that he's just as smart as Batman is and not just strongman. We kinda get close to this with Nolan's Bane but I feel if this universe keeps focusing on the Batman's detective side Bane would be another good villain for that.
Though I'll admit, I'd love for a Batman movie to embrace the fact that some of his villians are super powered or monstrous. I'm starting to get tired of this hardcore focus on realism, and trying tone down a lot of the more fantastical elements. But we're potentially getting away from the Grimdark crusader, maybe we can slowly amp up to more fantastical villians.
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Also, if they do do Robin... I kinda want them to go for Jason Todd. Dick Grayson gets all the love in media adaptations when they do Robin. I wanna see something different (much like with the villains) and Jason Todd seems the perfect candidate for Robin. Batman wants to be different, wants to be a symbol for hope and peace to help Gotham heal its scars. Well here we have a petty theif from a broken and abusive family, who has the sheer balls to try and steal from Batman... He's basically the embodiment of Gotham, the exact kinda person that if older probably would have been one of Riddler's followers. So take him in, train him to use his skills and anger to help make Gotham a better place. And no, I don't just want him to be brought in to be killed by Joker. I don't want him brought in just to make him Red Hood. I want to see Jason actually be used as a character who plays off of Bruce's desire to do and be better. It shouldn't be easy, it should be a struggle, but they should both make the other better.