Unlike in the famous film known as the Exorcist, there are no strange ghosts in the World. However, under the rule of the Great Cthulhu, the Lord himself is poised and ready to capture the mortals souls. The Mortal realm is yet to transcend to the godly realm of the Great Cthulhu. The Demonic possession is highly dangerous and mainly caused by the ownership of Pokemon Cards. These cards are inhabited by deadly demonchildren. These are incredibly dangerous in the right conditions.
Upon ownership of a Pokemon Card, (Important to omit an accent because that's french not English) one can either set the demon upon another's soul, or will absorb the demon unto themselves. It is very dangerous, just like Granny Fanny's Tinned Plums and/or peaches.