After Becoming a Background Character, I Became the Villain Boss

Note: Female-led story (with some ensemble-cast sections), no romance, monster-slaying and leveling, not a power fantasy

Lin Yu transmigrates into a book.

She becomes a pitiful background character with no parents, living in a remote mountain village.

Just as she is preparing to work diligently at being a good-for-nothing, she discovers that she is actually the biggest villain in the entire book?!

Lin Yu: I can't handle this kind of everyone-against-one plot. I just want to laze around...