User blog comment:B214/Volume 23 discussion blog/@comment-190.160.185.214-20170411002917/@comment-10330822-20170411020137

Technically, if we are going off of the mythology of the Bible, which if of course in this series should be taken with a grain of salt, Lilith was a human, not a devil. She was supposed to be Adam's wife and the mother of the Earth's children, but she refused to be submissive to Adam, and so he abandoned her.

After that, depending on your faith, Lilith married Lucifer and gave birth to the devils of the Underworld.

However, due to Rizevim's status as a pureblood, Lucifer would have either turned her into a devil, or she was a devil to begin with.

My guess is that she may serve as a power-up for Vali later on, since she is technically his great-grandmother. Otherwise, I have no idea how she would factor into the story.