Annilese Michel was a teenager from Germany in the 70s. She loved God and wanted to be a victim soul. A victim soul is someone who gives their life as a sacrifice to God by perfect obedience to his will. Usually, that is by consecration to religious vows, liturgical sacrifice, fasting, prayer and generous service to our neighbors. She was so fervent in her sacrifices that she would sleep on the floor as an offering of atonement. The Mother of God appeared to her and asked her to accept an extraordinary mission. She was asked to be possessed by demons and the souls of the damned so that the world could see. Annilese accepted and offered up her sufferings in reparation for the sins of the young. She suffered heroically though years of possession. At the end though, there were many hours of audiotape of demons speaking to the exorcist priests. She died from the violence of the demons. She wouldn’t eat or drink and she would hurt herself. She suffered so much! She will be declared one of the most greatest saints of all time! When she died she weighed only 68 pounds.
This website has some quotes of the demons from a book: http://dominiestemp.blogspot.com/2013/09/what-satan-and-other-demons-said.html