Oppression
Oppression is the next stage of a demonic haunting. The annoyances of infestation begin to increase coupled with more overt attacks on their targets. At this stage, the presence becomes more violent. The previous activity will likely continue, but now the demonic presence has gotten the occupants accustomed to the strange annoyances the objective changes to domination and oppression.
Think of this in terms of a frog and the boiling pot of water. If you dump a frog into the 
boiling pot it will jump out. If you put a frog in cool water and slowly heat it up the frog will boil to death. Infestation is the cool water warming up. Oppression is boiling.
If you subject a target to outright terror from the onset they will flee to any form of help they can find. If you start small and work your way up they are in over their heads before they know what to do and they feel like they have no recourse at that point and sit idly by suffering.
Oppression the tactics will change to visible shadow figures, scratches, bites, and physical attacks, to outright sexual assault as the subject finds they are awake but paralyzed in bed unable to move as they are sexually violated. The subject may find themselves or their beds levitated.
Understand sex is an act of creation. God creates, and God has given the man the power of creation while here on this earth. The demonic seek to twist and taint this act of creation which is why sexual perversion and sexual assaults are one of their favorite acts of the demonic.
During the oppression phase, the demonic seek to psychologically break their targets. They do this through financial stress, such as destroyed personal property, missing money, requiring the target to miss excessive work, etc. They also do this through sleep deprivation through constant physical assaults, noise throughout the night, slamming doors, or other means designed to keep people fearful, and unable to sleep. The message to the targets is clear, nobody, and nothing is safe or sacred.
Once a target has reached a certain point they break and give up, which leads to the next phase, possession.