Since I was young, I'd like to say about 6 I've had "imaginary friends". No I don't mean the ones you talk to as children when pretending your stuffed animals are real, but the ones that people determine you to have DID. I'm not saying that I do because I'm pretty darn sure I don't.
Thankfully, my "friends" have always been there to help me. At first as a child I didn't know what they were or who they were. I simply called them Dark and Light, names I chose because Dark always tried to get me to relax-be a child go play video games and have fun. While Light would scold me into doing what I should-being a good little girl and obeying my elders and being responsible. I know their true names now and even what they look like. I know about their lives and how they ended up coming across me.
They've helped me through my nightmares (nightly occurences since I was a child) and every day life. Helping me to get through situations I couldn't dream of on my own half the time.
I've met others like them and now have access to a "home" in my head that I can escape to where they also reside. I also have the ability to focus and zone out-leaving my body which sadly is defenseless and tends to flop over if i'm not laying down or in a comfortable position.
On one occasion when I did so I ended up getting hurt and the next day that wound appeared on my own body which has now spread into a skin condition on a quarter of my body. The dermatologist I saw told me its a skin disease that only shows up in third world countries-sadly I don't remember the name and don't care anymore-was too long for a normal person to remember. Simply use some Amlactin and thorough scrubbing and it's controlled.
I suppose what I'm getting at is I wonder if anyone else is like me. I've met a handful of people who have this ability and "people" who we love and cherish that others can not see. I've been possessed by them and no one knows the wiser. I know however the bad things that could happen if I were not careful and I've seen and been in a situation where I had to help someone come out of a possession.
I know that this is kind of vague. But this is a secret I've held onto for many years. All I know is that I am a host and a gatekeeper.
As far as the other spirits, it depends on your experiences with them to be able to say what they have come to you for.