Catwoman

She is the most well-known villainess from Batman’s rogues gallery. And Carla Gugino is the actress to portray an aging Selina Kyle. Come on – you would also be interested in seeing her.

And the fact is that she’s not a straight-up supervillain, which would make things even more interesting. Her relationship with Bruce Wayne could also play an important part in such a spin-off, just as her relationship with Gotham’s criminal underworld would. While Harley is definitely, at this point, at the peak of her stardom, Catwoman’s character has developed over the course of more than 70 years – so she is definitely more attractive from this point of view.

Catwoman is also one of Gotham’s Sirens, a team that also included Harley. So it all makes sense. This would also add a bit of tension between her and Harley, since Catwoman knows the secret identity of Batman. How would she keep it a secret?

I don’t know. But I’d be interested in finding out.