Assiah is the material world in which humans live. Demons can pass into this world by possessing anything that exists within it. It is the ultimate goal of Satan, the ruler of Gehanna, to make Assiah his own,. Specially-trained humans in the world of Assiah can exorcise Demons back to Gehenna through various methods. Any kind of contact between the two worlds is normally impossible, save for Demons who live in Assiah by possessing objects.