I have someone whom I love very much, and he's having a problem with, well what he considers is an entirely different entity that resides inside of him.

He's very troubled, and he asked me directly for help, I made him a promise that I would, and I have tried... believe me I have. However I am in way over my head and I have no other choice but to seek help from outside sources.

He describes this entity as a stupid child, one who resides merely to torment him, I refer to this entity as Leech because it seems to feed off of him.

I really have no clue how to deal with this stuff, it is not my forte, psychology is my forte.  

Hello...

I am seeing this entity as a manifestation of some part of him he is trying to repress. Has he done something bad in his childhood? Does he have guilt? I think you should put your psychology skills to work on him first before you assume it is an entity from the outside. I've heard of this before where a man/woman develops this "angry inner child" that can torment through dreams and/or waking hallucinations.

Please try and investigate this way and come back if you don't have success( come back either way, I'd like to know).

I wish you the best.

Tremoursequence

It is funny how I felt the same as FireRose while I was reading your posting before I even saw FRose's response to you. I almost, in my head, dismissed this demonic 'being' residing inside your friend's psyche or body. You say you have helped your friend. How?
I think before we arrive to conclusions of some low entity spirit residing within him, it is best to explore other 'earthly' avenues.

Good luck.

I am assuming it is repressed aspects of what was once himself. He cannot recall a lot of his childhood, he puts it this way "There was this other me, then the me that is now took control of this other, supressing him"

What seems like to me is this what him before he grew, and he never learned how to throw out the old. And because of that, it manifests itself in quite a few negative behaviours and so on. I'm trying to apply psychology to this situation and am not getting really wonderful results. I'm needing a different approach.

Have you tried taking him to see other professionals? Maybe hypnotherapy would be helpful to recall and deal with some issues from childhood.