I'm not sure exactly as I haven't read the novel in full, but surely the main character is the girl who wants to become the best villainess. There must also be other characters who either support her in her quest or oppose her, like other nobles or potential love interests.
The main character is the one with the goal of becoming the best villainess. She may have friends or servants who are part of her story. There could be antagonists like those who represent the status quo or those who are competing with her in the same 'villainess' space. Also, there may be characters from different social classes that she interacts with as she tries to achieve her goal, which all together form the rich tapestry of the story.
The unique concept of the protagonist aiming to be the best villainess is quite appealing. It offers a fresh take on the typical storylines. Also, the character development might be very interesting as she tries to achieve this goal in a world full of different power dynamics and relationships.
Well, of course, the main character is the one who becomes the 'true villainess'. There might also be a male lead, perhaps a hero or a love interest who is in conflict with her new villainous nature. And then there could be secondary characters like her family members, friends from before her transformation, or other villains in the story who she may interact with, compete with, or form alliances with.
Perhaps there is a love interest who has to deal with the protagonist's transformation into a villainess. His reactions and how he tries to handle the situation could make him an interesting character. Also, there could be a rival character who is constantly at odds with the villainess - to - be, and their battles of wits would be engaging.
The protagonist herself is very interesting. Since she has become a 'true villainess', her character development is something to watch. There might be a love interest who has an unexpected reaction to her new persona. And perhaps a rival character who challenges her in different ways.
There could be her family members like her parents. They might play important roles in the story, either supporting or opposing her at different times.
The main character is the protagonist who falls in love with the villainess. We often see the story from their perspective as they navigate their unusual feelings.
The main character is, of course, the villainess herself. She is at the center of the story. There might also be a love interest, perhaps a nobleman or a prince. And then there could be other antagonists who oppose the villainess in her new - found journey, like jealous rivals or those who want to uphold the status quo.
The protagonist, who is the reincarnated villainess, is of course a main character. She's the one driving the story as she tries to change her fate. Then there's usually a male lead, who is often part of the original story that she's now trying to rewrite. There's also the original heroine, with whom the protagonist has a complex relationship as she's now in the role of the villainess against her. These three are typically the main characters that shape the story.
In this light novel, aside from the villainess, there are her maids or servants who play important supporting roles. They might be privy to some of her secrets or be involved in her schemes. Also, there are often rival characters, like other noble ladies who compete with the villainess in various aspects, such as social status or the affections of the male lead.
The main character is often the person who favours the villainess. And of course, the villainess herself is a central figure. There may also be other characters like the original hero or heroine who play important roles in the story as they interact with the villainess and the one who favours her.