This manga is different from others in that it offers a fresh perspective and unexpected twists. The art is also distinctive, making it visually appealing compared to the usual offerings in the same category.
Not having read 'the maidens a novel', it's difficult to determine the main characters. But it's reasonable to think that the maidens themselves are the central focus. There could be different types of maidens, for example, a bold and adventurous maiden, a shy and reserved one, etc. And they may interact with characters such as a wise old woman who gives them advice, or a young man who causes some sort of conflict or romance in their lives.
Here, I recommend the Exquisite Seven Absolutes and the Seven Absolutes Demonic Sound Zither. Both books have plots about the Seven Absolutes. I hope you like my recommendation. Muah ~
Since I haven't read it, I can't say for sure. But I assume the 108 maidens are the main characters, and there might be some other supporting characters like wise elders or powerful adversaries.
The RWBY team - Ruby, Weiss, Blake, and Yang - could also be important characters in the 'rwby four maidens fanfic'. They might interact with the maidens, either as allies or in some cases, having to resolve conflicts. For example, if there is a misunderstanding about the maidens' powers or intentions, the RWBY team would be there to figure things out.
Since I'm not familiar with the 'the dark maidens light novel', I can't tell you exactly who the main characters are. But typically in a light novel, the main characters are the ones around whom the story revolves. So in this case, it could be the 'dark maidens' themselves, and there might also be some supporting characters like friends, family members or foes related to them.
You can make your character a savage by giving them a wild and unrestrained personality. Let them act impulsively and fearlessly, not caring about social norms.
The knight could be developed by showing his code of honor. For example, in every battle he faces, he adheres to a strict set of rules. His backstory might be gradually revealed, like he was once a soldier in a great war and now he feels a sense of duty to protect the maidens. The maidens, on the other hand, could be developed through their interactions with the knight. Maybe one maiden is initially shy but as she spends more time with the knight, she becomes more confident in her abilities.
Jaune is probably the protagonist around whom the story revolves. As for the Maidens, they are likely characters with special powers. They could be a group of female characters with different personalities and abilities related to elements like fire, water, earth and air. Their interactions with Jaune would be a major part of the story, as they work together or face conflicts within the story's universe.