you are a member of a noble family in a fantasy world, your family has a tradition of upon the 18 year after birth infusing a demon into the members body. This allows the demon freedom from the nether realms and power plus protection to the one being infused, all well as keeping the demon contained and controlled. The ritual was preformed a few days ago and you were told it takes a will for the demon to adjust and even be able to communicate, though you have gained some weak infernal powers