I just had to count it out for this thread haha--apparently Nocturne will have about 17 characters not including like, really minute bg characters or characters who show up only for a page or two. Five of those are the immediate main characters-- Lexi, Vespyr, Brandi and the two main antagonists, while the rest are support characters who will show up as the chapters go by.
The way Nocturne is structured is that each chapter is kind of like a mini-story in it's own right, in that each chapter focuses on a set of characters and has a problem and a resolution to come to within the chapter, all while contributing to the overall narrative of the murder mystery. Because of this, not every single one of the 17 characters is always relevant, so I feel like the number doesn't actually feel as large as it is to me haha!