I don't have specific information about the main characters in this light novel. But typically, the succubus herself would be a main character. There might also be other characters like a wizard or a knight who could be involved in her story, either as friends, foes, or love interests.
Well, it might explore the concept of a succubus in a unique way. Maybe it shows how she uses her powers in different situations. It could also be about her relationships, whether it's with humans she might be attracted to or with other creatures in the fictional setting. The story could revolve around her trying to fit into a world that might not fully accept her kind.
I'm not sure exactly who the main characters are without reading it. But it could be a new character created specifically for this light novel, or it might focus on a lesser - known Marvel character.
I don't know specifically as I haven't read the novel. It could be a lone hero type character.
The protagonist is of course a central character. However, without having read the whole novel in detail, it's hard to name all the main characters precisely. But generally, there would be characters who are in positions of power, like lords or generals, and those who oppose or support the protagonist in his journey.
The main character is the fated villain himself. There are likely also heroes or protagonists who oppose him, though specific details would depend on the novel's development.
Probably some rival characters as well. These are other wizards who are also competing for the title of Wizard King or have their own agendas that conflict with the protagonist's. Their interactions with the main character add a lot of tension and excitement to the story.
Since I'm not familiar with the 'I am death novel', I can't say for sure. But it could have a character who represents death as the main character. There might also be characters who interact with this 'death' figure, like a human who is trying to bargain with death for more time.
It's possible that there is a character who is in a state of transition or change. This character might be the central figure in the 'Here I Am Novel'. They could be facing challenges in their life, such as a career change, a move to a new place, or a shift in relationships, and through these experiences, they are evolving and coming into their own, which ties in with the title.
Obviously, Bella is the main character as she is the succubus. There might also be a love interest, perhaps a human or another supernatural being. For example, in some fanfics, there could be a vampire character who becomes intrigued by Bella's succubus nature.
Obviously, Harry would be the main character as the title indicates his transformation into a succubus. His friends like Hermione and Ron are likely to be important secondary characters. They would play a role in either helping Harry come to terms with his new nature or being initially suspicious of the changes in him.