In this post I will go over what I believe are the types of possessions:
Emotional Possessions- are possessions in which the influencing spirit (s) cause the possessed person to feel a certain emotion negative or positive, and feed off of that emotion/energy. These possessions are commonly ignored as depression or other mental illnesses.
Environmental Possession- are possessions in which the influencing spirit (s) effect the environment by causing objects to go missing or possible float around and even hit people. In addition, the feeling of an area can be affected by an environmental possession. Also, spirits can physical attack people with this type of possession, by even causing cars to hit people or car crashes (very rare but there is a few reported cases).
Mental Possessions- are possessions where a spirit influences a person's thoughts and reasoning processes as well as their senses. These possessions can cause a person to go insane or temporally insane. By doing this the spirit can cause the possessed person to attack and kill other people, or do other things it desires.
Physical Possessions - are possession in which the spirit controls/takes over a person physical body. These possessions happen mostly after the spirit has a strong mental possession. Then by using their control over the mind they take over the body and do with it as they please.
Free Willed Possessions- are the most dangerous type of possession since the possessing spirit (s) pretend to be a guardian angel or spirit guide. In these possessions the spirit acting as a guide or guardian tells the person false advice and eventually causes the person to do what they want by saying that the person will help the world or someone when the person is exactly only doing what is in that spirits interest. Basically, the spirit blinds a person with their beliefs/faith into doing anything. By doing this I believe spirits cause religious wars, and murders/suicides. In addition, in exorcisms the demon can pretend to leave but only take the appearance of an angel and either continues the possession as a free willed possession or some other type of possession.
Once again feel free to add anything that I missed.