I already answered this, but discernment is the prime tool in deliverance.
You can also add yawning as a common manifestation when an evil spirit departs.
You are just arguing from ignorance, not knowledge. But Mark9 is just one example among many and such violent reactions are very infrequent.
And FYI, in my first experience of being set free, the man simply laid hands on me to pray, and I ended up across the other side of the room.
According to my wife, I flew across the room like I'd just been slugged by John Wayne in a bar fight, although I felt and knew nothing when I came too a few moments later.
Do you seriously think it helps your case, quoting silly stuff about other people elsewhere that's got nothing to do with me?
Its called a straw man argument, congratulations, you win every time, (in your own head).
You really know nothing at all do you. The amount of control a demon has over a person is hugely variable, from hardly anything, to almost but not quite total control. remember, the man with the Legion of demons, he still had sufficient freewill to approach Jesus for help.
This nonsense about Oppressed or possessed, is not found in scripture. The word is simply "demonised". An scripture always shows demons being cast OUT of people, proving they were inside them.
Except you've not presented the truth, just your opinion.
When it comes to casting demons out, scripture makes no differentiation whatsoever as to whether the victim was a believer or not. Therefore it is up to you to demonstrate they were unbelievers!
But here's the commandment of Jesus.
Mark16v15And He said to them, “Having gone into all the world, proclaim the gospel to all the creation. 16The one having believed and having been baptized will be saved, but the one having disbelieved will be condemned. 17And these signs will accompany those having believed: In My name they will cast out demons...….........
Being that you are such an expert on the subject, please tell me how many times you have cast demons out?