I think you can have most villans from DC in any grounded Batman film
1. Joker (scars and makeup)
2. Penguin (surgery and deformities?)
3. Riddler (crazy smart crazy)
4. Ivy (poison femme fatal ,(no plant control needed, but she could use certain plants that actually do squirt or launch seeds)
5. ScareCrow (see Nolans, I actually think they could go further with the creep factor ok this)
6. Black Mask (as is)
7. Mr Freeze (nitrogen is already dangerous, and weaponizing it is not a huge leap.)
8. Croc? Super freak huge guy with genetic skin disorder who files his teeth down?)
9. Bane (I am fine with a Venom story, adrenaline mixes with PCP like substance)
10. Harley (crazy psychiatrist, no adaption needed)
11. The Ventriloquist (stupid but possible)
12. Two Face ( easy )
13. Hush (also easy) and I presixt the next story in The Batman part II with Court of Owls
14. Zazss: Serial killer story! Definetly could fit in this universe!!!
Now the tough ones.
1.Man Bat: Straight “jump the shark” territory here, this is a Marvel or Superman villan and has no business being in a Batman story.
2. Clayface: I do like the character, but its too Meta for my Batman sensibilities.
3. Mad Hatter: again, love the character for the comics, but trying to use some kinda mind control chip, just will be too much to fathom, unless hes performing brain surgery on people)