We live in a world of 'opposites'.....black/white, hot/cold, asleep/awake...God/Satan, good/bad.
If we didn't have opposites, we wouldn't have adequate balance in life. I don't think that we could learn anything if everything was straight forward love and peace all the way. It would be nice....but I think that life would become stale. There has to be some form of conflict. As it was in the day before the Garden of Eden .....life went on and on...love and peace.....soon, hum drumm....and then the apple was eaten. That was probably the best thing for mankind ever...to eat that damn apple. Now things become interesting.
I can tell you that for years and years, I have on occassion had experiences with bad forces. When I was in my teens, I dabbled in some things that maybe I shouldn't have. Whether that is what attracted these entities to me I don't know....but at that time of dabble, was also the height of alot of trouble I was having with these darker forces. Even to this day, every once in awhile. when I sleep, when I am my most vulnerable, I am awaken with the struggle happening of an entity or dark spirit trying to take over my soul/body......literally. And it is the most scarey ever experience ever to go thru.
However...I think the worse thing that I ever experienced was around 1999, when I was in college completely a semester in childcare...we were doing an art project for kids. It involved using 2 colors of paint and a sheet of construction paper. Fold the sheet in half dab your 2 colors on one side only. Fold the sheet in half and then gently apply pressure or rub. Open the sheet up and observe a neat mingle of color and see the reverse on the opposite side of the one half.
All was well.....all the students were looking at their creations and talking.
Class was minutes from ending. I was running behind, as usual....I was one of the last to get to the final stage of this art project.
My girlfriend was standing next to me when I opened my paper up. Once I opened my paper....I was immediately horrified. What was literally developing in front of my eyes, was beastly facial shape....face wide at the forehead and narrowing at the jaw..this 'thing' had blazing red eyes...and you know, I never even used the color red as one of my 2 colors....so where did that come from? This pic developed as we watched it....like watching a pic develop in a dark room...and became perfectly clear. I was shaking so much I could hardly hold the paper....I started to cry...my girlfriend started to cry...and then others gathered to see what was going on. Their mouths dropped open when they saw what was on the paper. I could hear: poor sandy...omg.....and 'ahhh's' and '&#E$^*&^*'..........I threw it in the garbage can. I should have burned it. But I wasn't thinking.
I suddenly became very afraid to go home....I felt that this was a warning of something really bad. But I had to go home...my kids were there, waiting for me. I gave my girlfriend a ride home and we talked about it all the way....we were both crying like babies...both scared to death of what happened and not knowing what the significance of it was.
I will tell you that when I got home, my husband (not anymore) was there...got home early. I was so scared to walk into the house not knowing what I was going to find. But, my kids were in there and I had to go in.
What I found when I got inside was.....well, I am not going to get into detail...but it changed my life and  my kids lives forever. It was a scene that I nearly could have killed someone and not cared at the consequences of.....it was everything that confirmed my worst fears of coming home too.
I should have burned that picture.
Yes, I believe that there are darker forces out there that are ready to do their deeds at the moment that opportunity opens up.

One other thing. Your soul is a huge thing. I doubt that another being could take over the entirety of it. Perhaps a being could try to take control of your body, or influence your mind. But I don't see how they could take over your soul.