In this video, my Level 21 Barbarian helped with not one, but two exorcisms. She also killed a whole lot of Marauders and Ghouls along the way.
This was the video in which I realized that my Barbarian runs out of health and fury very quickly. I learned that pushing her through the fighting increases her fury. If/when she gets overwhelmed by the mob of monsters – she comes back at full health. This is not a perfect solution, but worked well enough for me.