I think Nina as a character is good, but could have been more than what we were given?
As far as female characters in anime go, she’s far more fleshed out than your usual fare, and even takes center stage plenty of times, both with her motive to kill Johan and the entirety of the Red Rose Mansion. She winds up going through her own mini-arc that somewhat parallels Tenma’s story, in that when she’s faced with Capek, she comes very close to shooting him – and in fact Johan seems to believe that she will, if Capek is to be believed – but in the end she’s able to make the choice not to do it.
She’s gone through a lot in her life but she doesn’t really let herself get carried by other people in order to solve her problems; she goes off to do things on her own – which sometimes results in her needing help, but in fairness Tenma and the other Monster Men are just as liable to do something stupid and need someone to bail them out. In particular how Nina and Tenma’s dynamic works really characterizes a lot of the show for me; it’s the acknowledgement of what you think you need to do, while the people around you are able to see other solutions that are far less grim. They’re constantly at each other with the “DON’T SHOOT” which I think bothered some people…but for me it really just solidified both their characters and their stories.
Personality-wise she’s also fairly relatable…being a quieter kind of girl who usually does things on her own and doesn’t think to ask for help or want to involve others…I resonate with those aspects of her. The whole of the Red Rose Mansion and her repressed memories are an interesting aspect of course, but I’m less interested in that than in her personal growth as a result of those aspects.
So now where I think that she could have been more…
On the one hand, there are a couple character elements that seem to get conveniently pushed aside. In particular she’s a complete badass when she and Tenma confront that guy at Heidelberg Castle, but we only really see that side of her a sparing few times. There were other occasions where it could have come in handy I think.
More importantly though I feel like her psyche wasn’t as explored as it could have been. For one thing, the scene with Gillen where she becomes a very dark individual – and then at the Vampire’s House looking at the sketches – we get something very interesting….but it’s never really given a good explanation, nor is it given the same depth as Johan’s mind is. Nina for the most part is kept as a surface level character – we get to understand her motives and her as a person, but we don’t really get to see a lot of what made her mind the way it is. We see bits of it, but not enough, I think.
So overall I like her! I just feel like more could have been done.