The Nun..

Valak Was Once An Angel, Who Was Rejected By God.. However, a fellow angel named Lucifer rebelled against God and gathered other angels to become his followers, including Valak. After the rebellion, Lucifer, Valak, and the other angels were cast out of Heaven. Lucifer became Satan and Valak and the other angels who were cast down became demons. In the process, Valak was not only stripped of its status as an Angel, but was also stripped of its special powers it had as an Angel. Valak appeared in written form in Pseudomonarchia Daemonum ("The False Monarchy of Demons”). The text was an appendix in the 1577 grimoire De praestigiis daemonum (“On the Tricks of Demons”), by Johann Weyer, who himself was a Dutch physician, renowned occultist, and demonologist.