Demons have a long history of interfering in the affairs of the physical world and the lives of people, though not always with the goal of subverting souls. They act as tricksters and create annoying disturbances. More seriously, they cause illnesses, insanity, disasters, and bad luck.Some hold long-standing grudges against humanity.
One demonic activity that fascinates people most is possession. Beliefs about possession are universal and ancient, such as possession by the zar of Middle Eastern lore and the kitsune of Japanese lore, who demand attention and gifts. Everywhere in the ancient world, possessing demons caused illness and insanity.