Since I don't have specific knowledge about this light novel, it's hard to name the exact main characters. However, based on the title, we can expect a central character who feels at ease in the darkness. There may be other characters around this central figure, such as a mentor - like figure who tries to guide the character's understanding of their comfort in the darkness, or a peer who shares a similar experience or at least tries to empathize with the main character's situation.
One of the main themes could be the relationship with darkness. Maybe the protagonist finds solace or a sense of self in the darkness that they don't find in the light. It could also explore themes of isolation, as being comfortable in the darkness might imply a certain detachment from the norm which is often associated with light and brightness.
I'm sorry, I don't know who the author of this web novel is. There could be many web novels with similar titles, and without more information, it's difficult to determine the specific author.
I'm not sure if it's a popular novel. I haven't heard much about it in mainstream discussions, but that doesn't mean it doesn't have a dedicated following.
Kazuma is one of the main characters related to Darkness. Their relationship is full of comical exchanges. Also, Aqua and Megumin are important characters in relation to Darkness. They are all part of the same party in the story.
I'm not sure specifically as we don't have more details about the story. But it could be an ordinary person who becomes a hero, like a young girl who finds a cure for a deadly disease in a world full of suffering. She would be one of the main characters.
I don't have enough information to say who the main characters are as I don't know the particular 'a light in the darkness story'.
I'm not sure exactly as I haven't read it. But perhaps it could be about a character who finds solace or a sense of belonging in the darkness, maybe in a metaphorical sense like being an outcast in society and feeling more at ease in seclusion which is symbolized by darkness.
I'm not sure as I haven't read it. But usually in such novels, there could be a brave hero or heroine who leads the fight against the darkness.
Not having read the 'darkness over me novel', I can only speculate. There could be a strong - willed hero who is trying to emerge from the 'darkness' that surrounds them. There might also be some supporting characters, like a wise mentor figure who tries to guide the protagonist out of the 'darkness', or an antagonist who represents the source or the manifestation of the 'darkness' itself.
Since it's a Twilight fanfiction, it might focus on the Cullens as the main characters. One of them could be the one to bring the 'light in the darkness'. For instance, Carlisle with his moral compass and leadership could be the central figure in a story about guiding the family through a difficult time in the Twilight - like world. Or perhaps it could be a new Cullen - like vampire introduced in the fanfiction who plays this role.