Demon
The contemporary Roman Catholic Church unequivocally teaches that angels and demons are real beings rather than just symbolic devices. The Catholic Church has a cadre of officially sanctioned exorcists which perform many exorcisms each year. The exorcists of the Catholic Church teach that demons attack humans continually but that afflicted persons can be effectively healed and protected either by the formal rite of exorcism, authorized to be performed only by bishops and those they designate, or by prayers of deliverance, which any Christian can offer for themselves or others.
Blue Exorcist
In contrast, there are those called Exorcists, people who train to destroy demons who act in a damaging manner in Assiah. With more than two thousand years of existence, this group has several branches all over the world, being secretly under the command of the Vatican itself and acting in a subterfuge way to the masses.