I can't really say terribly much about Remi as a natural good person. John is the only one I view as a natural good person, for his strive to better the world actually led him to tackle it from its core. Remi didn't reject or embrace the system. She was born with power and lived a good life comparatively to most folks. Sure, she was 'nice' in that she didn't go out of her way to harm anyway, but she also doesn't often go out of her way to help people either. She's more neutral, it's simply that this world is so skewed that people who are 'neutral' are perceived as 'good' simply because they're so far above the norm when it comes to morality. But I honestly can't see Remi as being naturally good because she was content with the system, whereas John wasn't. Similar to Seraphina before she met John. They didn't really hurt folk, but they made no attempt to uproot the system, if they even saw anything wrong with it. As it stands Remi is only acting on behalf of her dead brother, not because she truly wants to do good. The only character I can count as a 'good' character is John and his father, which is why it's terrible to see him do bad things as it's so far out of character for him, and the opposite of what he strives to do. Perhaps John was like Remi once, but changed due to his past as well as his father's influence. He couldn't stand the system any longer, and thusly became good through his honest attempts and persistence to change it.
Thinking on it now, it seems like John mostly wants to be left alone, though from his interactions with Seraphina, it's clear that he has a strong passion to do something more. Not because someone close to him died, or because he hates his powers, but because he tires of such a vile world, and honestly wants to change it to be one where people aren't discriminated against.