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.
The Sorceror King himself is surely one of the main characters. There may also be his loyal followers or servants who play important roles.
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.
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.
It's difficult to say exactly who the main characters are without more information about the particular 'the wizard world light novel'. However, it's common to have a protagonist wizard who has a special destiny or power. This wizard might be opposed by a powerful enemy. There could also be side characters like a wizard's familiar, which could be an animal with magical abilities, and other wizards from different wizarding schools or factions that play important roles in the story.
Well, clearly the daughter of the dark king is a main character. There might also be the dark king himself. Maybe there are some servants or advisors in the king's court who play important roles as well, like an old wise advisor who has been with the king for a long time and now has to deal with the daughter too.
Since I haven't read it, I can only guess. Obviously, the king's daughter would be a main character. There might also be the king himself, the queen, and perhaps some servants or guards who play important roles in her life.
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.
Power is likely a main theme. Since the title is 'I am a king', it probably focuses on the power that comes with the position. Also, leadership could be a theme.