Ah yes, I wrote a short description of something in the post "Magic and madness" I can write a longer story here.
I have always been into the more hardcore processing practices, meaning like taking mantras, prayers and spamming the hell out of them, extended sessions, pounding and smashing the spiritual system to get something going. Pushing the limits and trying to break the records.
During the first 8 or so years the following happened.
So I read a lot of pages of psalms per day, this was mixed together with the Quran and also some Hindu mantras. On the top of that I did saint work and at some point went to the church for communion. The energy stacked so massively that I felt like having nuclear energy stacked inside me. Imagine the cocktail with a cherry on top, Book of Mormon yet another different feeling energy. Yes I mixed the BOM in there as well. Cycled everything, cover to cover readings and everything else.
What happened was mega sensitivity which unlocked quite fast. Already within months I was very open and the first year added another 300%+ to the openness. As openness I am talking about "mega" increased awareness of feeling energies everywhere at all times. Feeling the mantras and prayers instantly going through you and sensing states of ecstasy from just some prayer readings.
I remember going to a cemetery in this state and feeling the necromantic energy pour through the third eye right into me, feeling so high in head.
At first very high, then a taste of soil for days, imagine feeling like you have eaten literally mud or something. Then the sorrows and sadness, emotions of the people, feeling it suck away all your energy and replacing it with the necromantic essence. Feeling so dead and disgusted for days. Yes at first the energy high itself was wonderful but it lasted only a day and then something started going wrong.
The possessions which came from the spirits entering me and having to be exorcised out is the point of this story. Several cemetery cases and a couple of others from grimoires.
All because....
I realized that you should not really mix together too many different practices, if you work mainly with the Christian stuff then stick to it, if you are into Sufism then stick to it - only 90%+10% is acceptable, else you screw up everything, feel as if one type of energy is being erased by another, and yet another (Hindu), erasing one program with another. All this leads to holes in the system, empty gaps through what anything can come in, all the energies.
What did I learn? I did figure out the methods that can be used to do self exorcisms, then I figured out how one can attain massive energy sensitivity. Taught people the practices and watched them level up.
You will come back changed, when you get such possession experiences you will always remember them. There's no way to forget something like that. It makes you respect and understand that there's a lot more than meets the eye and you have to be careful with the practices.