insidious, I did have an experience that reminds me of yours. A protector ego state seemed to come out of nowhere, and there he was. We shared consciousness for about 3 days and he told me all kinds of stuff. Stuff I never knew! I felt very strange that I had this other person inside of me and I felt especially strange that he was a male! (I had 3 younger ego states, all of me at younger ages, but not a male and not someone who was not me, if that makes sense.) This protector was a young male in his twenties, quite brash, with more courage than I. I found out he had conversations with my girl ego states that I was not aware of, especially the teenager. I can't believe this stuff unknown to me goes on in my head! After a few days he was driving me crazy and I felt like there wasn't room for us both in my head. I felt like I was getting squished, like he was crowding me and taking up too much space. So at last I told him rather forcefully to leave me alone, and he went away. I felt bad about that. When I met with my therapist, I told him about this guy and he reassured me that he was just an ego state, not an alter like in DID (because he doesn't take over so that I am not conscious or in control). My therapist did a little couples counseling with me and the guy, even though he wasn't there. He has never come back in the same, overt way, and I feel bad about that, as if I chased him away. I feel like he must be there still inside of me, and sometimes I see him in the reactions I have to certain circumstances, and it makes me smile (or get frustrated!). It actually makes me feel good that I have someone inside who is strong and looking out for me.

I think if you were my therapist's client, he would probably want to work with you and your protector, and do some family therapy with you so that you could learn to get along with other, and so that the protector would stop being mean and domineering to you.