Defiled Advent.

At Etoile Private School, in the journalism club, Runa, Reina, and Miyu activate the Angel Maker app, which triggers a tragedy. They become magical girls and fight against deformed monsters, but one day, they are captured and raped by them. Magical girl Erika rescues them but warns that continuing to fight will attract more attacks. It turns out the app has been cursed by fallen angels. Erika fights against them, but her heart becomes corrupted.