Well, it depends. Honestly, I don't understand your question, but...
Casting or summoning demons can be performed by a Satanic ritual. Different types of demons fulfill different types of tasks for their summoner, but it comes at a cost, most likely a prized possession (sometimes even your soul!) I won't go too much into detail with that, but if you summon a demon, others cannot see it, and breaking the demon's agreement will result in a blunt death.
If you mean by exorcism, yes.
While movies about exorcism are true, I recommend that you see The Conjuring. It's one of the best true Horror movies out there, but everything that they say in the movie is true. Do not perform exorcisms without proper training and without proper supervision, because it may result in multiple deaths. It's very dangerous, and while the rewards are high because you banished a demon, it comes at a cost if the exorcism was not performed correctly. Priests that have had years of training to become an excorsist fail in being able to properly banish the demon without any type of negative result almost all of the time. My advice is: get a professional to perform such a task. Nobody has the gift and ability right off of the bat.
The cast of Demon - 2005 includes: Anna Nugent as Demon Eoin Ryan as Angel
The disciples were unable to cast out the demon in the book of Luke because they lacked faith. Jesus told them that their faith was too small, and that is why they were not successful in driving out the demon.
The cast of Demon - 1911 includes: Mikhail Tamarov
The cast of Jeff the Demon - 2009 includes: Will Arnett
Demons are supernatural beings, they are a completely seperate thing from human. While it may be possible to be possessed by a demon, you cannot be a demon, at least not in your physical form.
The cast of Demon Crayon - 2007 includes: Richie Dale Cole as Demon Driver Cameron Mircovich as Cameron
The cast of Waltz of the Demon King - 2011 includes: Robert Fleet as Demon Catherine Taber as Cosett
The cast of Demon - 2008 includes: Ray Boulay as Demon Eugenio Carvalho as Ghost of Fiance Katya Morenets as Tamara
There is no common knowledge or reference to a demon or angel named Philatanus. It is possible that this entity is fictional or from a niche mythos.
The cast of The Demon of the Derby - 2001 includes: Ann Calvello as herself
The cast of My Demon Nights - 2004 includes: Linnea Quigley as herself
The cast of The Demon Dog - 1911 includes: Hay Plumb as The Father