I'm not entirely sure as I haven't read it specifically. But generally, a 'villainess' light novel might be about a female character who is initially seen as a villain in a story, perhaps in a fantasy or fictional setting.
It's likely about a vampire in a chibi (cute, small - styled) form. Maybe it tells the story of this unique vampire's life, its adventures, relationships, and how it copes with being a vampire in a world that might not fully understand it.
Most chibi tomoe fanfics are known for their vivid descriptions of the chibi character. They tend to focus on the simple joys and small - scale problems that Chibi Tomoe faces. Such as in 'Chibi Tomoe's Little Mishap' where Chibi Tomoe loses her favorite toy. These fanfics also often have a lot of colorful settings to match the cute nature of Chibi Tomoe.
To draw manga chibi well, you need to focus on exaggerating the features. Make the heads larger, the eyes super cute, and simplify the body proportions. Also, use light and bold lines for emphasis.