The main character is, of course, the human who has been reincarnated as a dungeon core. Their past life experiences as a human shape their actions and decisions as a dungeon. There may also be some key adventurers who are constantly trying to raid the dungeon. They are sort of the antagonists from the dungeon core's perspective, but they also have their own backstories and motives.
Well, the main character is the human - turned - dungeon - core. This character has to adapt to its new form and all the rules that come with being a dungeon. As for other characters, there could be a guild master who sends adventurers to the dungeon. The guild master might be interested in the dungeon's resources or just in the fame of having his guild conquer it. There could also be a mysterious old hermit who has some knowledge about the reincarnation of the dungeon core and might try to either help or hinder the dungeon's growth, depending on their own motives.
Typically, the protagonist is the reincarnated dungeon core. They are likely to have a complex personality, influenced by their human past. There could be a mage or a warrior among the adventurers who stand out. For example, a powerful mage might be able to detect the unique nature of the dungeon core being formerly human and try to use that knowledge to their advantage, either to destroy the dungeon or to control it. And there might be other dungeon - related characters like the monsters that the dungeon core has to manage and direct, which can also be considered important characters in a way.
One unique feature could be the perspective shift. Instead of the usual hero or villain, we get to see the world from a dungeon core's point of view. This allows for a fresh take on world - building, as the dungeon core has to manage resources, create traps, and deal with invaders in a very different way compared to a human character.
I don't know specifically since I haven't read this light novel. But typically, there would be the dungeon master as a main character. There might also be some important adventurers who are either friends or foes of the dungeon master.
Well, it could be about a character who becomes a dungeon master through the core. This character might face numerous difficulties such as dealing with powerful monsters that inhabit the dungeon, competing with other dungeon masters if there are any in the story. Also, the story may include how the dungeon master uses the core's capabilities to build unique and dangerous dungeons to attract or deter adventurers.
One unique feature is the concept of being reincarnated as a dungeon core itself. It offers a fresh perspective in the fantasy genre. Usually, stories focus on heroes or villains, but here, the dungeon becomes the center of the narrative.
Well, in dungeon core fanfiction, the guardians of the dungeon are often popular characters. These could be powerful monsters that are bound to the dungeon core. They have a strong sense of loyalty and will fight to the death to protect the dungeon. Some fanfictions also feature wise sages who visit the dungeon to study its unique properties. They might give advice to the dungeon core or try to understand the secrets of its power. And then there are the thieves or rogues who try to steal from the dungeon, but their sneaky ways and narrow escapes make them interesting characters.
The protagonist is a young adventurer named Alex. He's brave and has a strong sense of curiosity, which drives him to explore the dungeon. Then there's Lily, a mage who teams up with Alex. She's smart and her magical abilities are crucial in many situations.
Perhaps there is also a mysterious old sage in 'the dungeon master light novel'. The sage could be a source of knowledge for the dungeon master, guiding him on how to improve the dungeon, manage resources better, and deal with the powerful entities that lurk within it. This character could also have his own hidden motives which add to the complexity of the story.
I'm not sure exactly who the main characters are without reading it. But it's likely to have a protagonist who is in charge of the dungeon defence. Maybe a brave warrior or a clever mage.
Perhaps there is a mentor figure, an experienced dungeon creator who guides the protagonist. And also, there might be some adventurers who interact with the dungeons created by the main character, and they could be considered important characters as well.
I'm not sure exactly as I haven't read it fully. But typically in such novels, there would be a brave adventurer as one of the main characters who is determined to master the dungeons.