Possession

Possession is when a physical being is taken over by a non-corporeal being such as a ghost or demon.  When a being's Aura Network is compromised, another spirit can enter in and begin asserting themselves.  If they succeed in completely subduing the ego of the host soul, then they are able to use the body as they wish.  However, if the host soul begins asserting itself and regains its sense of self it can expel the foreign spirit.
Barring the spirit leaving of its own free will, the only cure for Possession is Exorcism.  When performed by people without Power, the rituals of Exorcism generally entail trying to reach the consciousness of the host and expel the presence by having the host reassert himself.  For people WITH Power, it is generally easier as they can sense the foreign spirit and by cloaking themselves in Aura can manually force it out if they are of sufficient strength.  Once the foreign spirit is expelled from the host, it usually loses cohesion and vanishes back behind the veil.  Particularly strong spirits though can occasionally make the jump to another host provided one is in the immediate vicinity, but generally following an exorcism a rogue spirit does not have the strength to possess someone of any reasonable fortitude.
==Types of Possession==
The nature of Possession differs depending on the spirit doing the possessing.  If the being is a ghost or low level demon then the host is merely at the whim of the spirit dominating them.  However, if a devil or god is possessing a person, they become a conduit for their incredible power which can occasionally damage their body and even prove fatal.
===Ghost Possession===
The most common form of possession throughout the Universe is domination by a Ghost which has managed to force itself into a mortal body and dominate the host's spirit.  In the case of this form of possession, a spirit has taken over a mortal's body in order to do some task and they are only able to use whatever abilities their host naturally has.  Occasionally powerful ghosts are able to manifest telekinetic or telepathic powers through their host, but this is a rare occurance.
===Demonic Possession===
When a person is possessed by a spirit from Hell it is called Demonic Possession.  Generally this is done by lower level demons, as they are the only ones able to breach the barrier which divides the Planes and they will possess mortals in order to further the plans of their Devil Masters.  In the case of possession by Devils, the act of exorcism is much more difficult.  Because Devils' power prevents them from being able to truly assert themselves across the Barrier between the planes, being possessed by a devil can only happen in extremely rare circumstances.  In both known cases, the host was in an area where the dimensional barrier was weak or otherwise compromised.  In one case the host was a willing vessel for the Devil, and in another the devil managed to slip and gather her strength for years before taking over the host.  In general, a being under demonic possession has numerous grades with the host taking on more and more demonic features the stronger the demonic entity possessing them becomes.  When a devil achieves complete domination of its host, the skin and hair turn completely white.  This is the indicator that a material being has been completely tainted by infernal power.
===Divine Possession===
Divine possession is functionally identical to Demonic Possession.  In this instance a God will astral project into the body of a mortal being, where it is generally a simple matter for the greater spirit of the God to dominate the host mortal.  Once in the host body, a God has access to all their powers, though to a far limited degree.  Generally the containing of a God's power will cause damage to the host body's Aura Network.  In the case of benevolent gods they will keep their power usage to a minimum to avoid the corrosion of their host's body.  Generally on their way out they will heal the Host body leaving them better than they were before the God possessed them.  Survivors of divine possession occasionally find themselves with supernatural powers left behind by the God.  Malevolent gods though will operate without care, casually burning out their host body and leaving them a drooling mess in the event playing host to a god didn't outright kill them.
==Notable Instances==
Jaxx Parro: Parro was possessed by the Devil Alastor who used her as a vessel to advance Lilith's plans on the Midplane.
Kara: Kara became the physical vessel of Lilith in her plans to obtain the Bloodstone.  Lilith entered Kara's body and remained dormant for years before asserting herself, gaining complete control over the saran girl.  Cain was able to touch Kara's consciousness through their Bond, but still required a great deal of effort and magical sigils to force Lilith out of her.
==Trivia==
- In his youth, Johnny Duke encountered people on occasion met people under demonic possession and was able to expel the foreign Aura by virtue of his own powers.  This proved to be quite the conundrum to people professing "holy powers".  However, the tendency of holy charms to burst into flames in his presence combined with the demonic spirits seemingly recognizing him caused his then girlfriend Alexandra Knight to suspect that he might be a demon himself.