Unlike angels, demons have the ability to possess the children of clay. By leaping into a body, they can take control of
that persons actions. The victims spirit is still inside, but they have lost control. The greater the
person's faith, though, the more difficult this possession is. The demon must make a successful power roll against the victims faith score.
Possession is not an instantaneous thing. Once the demon inhabits a body it takes some time for the process to be completed. During this period, the demon is making connections with the subjects system and gathering the strength needed to assert himself. This strengthening process can take up to a week to complete, during which time there are no signs that the person is possessed.
The emergence of the demon is a gradual thing. At first, the demon will only be able to take control for short periods of time. As the demon grows stronger, though, he will be able to subvert the consciousness of the child of clay for longer episodes. Eventually, the original soul will only be able to break through for short moments.
The demon must constantly stay with the subject during the possession process. If for any reason, the demon is forced to leave the body, the possession must once again start from scratch. It is often times much more difficult for a demon
to possess a person for a second time.
Humans need not resist this process, though most do. Any child of clay can willingly give up his body for
possession. In these cases, the possession process follows a
more accelerated rate.
Demons possessing the children of clay are very difficult for angels to spot. This is especially true during the strengthening period. Once the demon begins to manifest itself, though, its behavior is usually a clear give away to its presence.