Exorcism
In Catholic practice the person performing the exorcism, known as an exorcist, is an ordained priest. The exorcist recites prayers according to the rubrics of the rite, and may make use of religious materials such as icons and sacramentals. The exorcist invokes God—specifically the Name of Jesus—as well as members of the Church Triumphant and the Archangel Michael to intervene with the exorcism. According to Catholic understanding, several weekly exorcisms over many years are sometimes required to expel a deeply entrenched demon.
The Exorcist
In "Angel: Earthly Possessions", a spin-off comic story based on the TV series "Angel", protagonist Angel finds himself dealing with a priest who performs exorcisms, but comes to realize that the priest is summoning the demons for him to exorcise in the first place. He also makes a note of "The Exorcist" film, noting that the vision it created of possession actually made things easier for possession demons by making it harder for humans to know what to expect from a possession.