Not having read the 'City of Darkness Graphic Novel', we can only guess about the main characters. They may include a young protagonist who discovers some dark secrets about the city and decides to take action. There could also be an older, wiser character who has seen the city's decline over the years and serves as a guide or mentor to the younger characters. And perhaps there's a villainous character, someone who benefits from the city's darkness, whether it's through illegal means or by controlling the power structures within the city.
I don't know the main characters in the 'City of Darkness Graphic Novel' as I haven't read it. But they could be some kind of anti - heroes trying to survive in the dark city.
Since I haven't read the graphic novel, it's hard to say exactly who the main characters are. However, they might be ordinary people thrust into extraordinary situations in this city of darkness. They could be a detective - like figure trying to solve the mysteries of the city, or a group of rebels fighting against an oppressive force that is part of what makes the city so dark.