Is There a name for this disorder? is it even one?!

Is There a name for this disorder? is it even one?

Ok, heres the deal. This is going to sound stupid, but this is the best way to describe it. In the show yugioh, the main character has this sort of alter ego/ spirit living inside of him. This is what i have, except that it goes by a diff. name and it does'nt really take over me. It's amost like a consciense, but seperate from myself. Its almost like i am a host for this...spirit? It doesnt stop there however. He has a whole life story. Am i just being over imaginative? Is this a disorder? if so, what is it called? Thanks!

I've never seen the show, but what you describe sounds most like DID, however a diagnosis here is not possible based on the info and without a diagnostic evaluation. Being aware of another part and being able to communicate internally with that part does not preclude the diagnosis as someone suggested, but rather may be evidence of co-consciousness. It may also be imagination if you are aware of having created this persona and consciously embellish its life story and if there was never a period where you experienced "time loss" which is indicative of the dissociative process. The following is an excerpt from a previous answer I've given regarding DID:

DID (MPD)

DID is the existence of two or more separate personalities or personality states within one person, with each alter having distinctly different ways of thinking, feeling, behaving and relating to the world and distinctly different memories, each part having amnesia for the other parts' memories. It is born from repeated and severe abuse and involves the defense mechanism of dissociation and generally develops before the age of 10 as children are far more likely to dissociate.
DID is often misdiagnosed and it is very common for a person to have had multiple different psychiatric diagnoses before it is definitively identified as DID. The symptoms frequently overlap with symptoms of schizophrenia, Bipolar Disorder, Depression, Anxiety Disorders (all), PTSD, other Dissociative Disorders and Somatoform Disorders as well as Borderline Personality. It requires extremely careful assessment and a high level of trust by the patient before alters reveal themselves. The diagnosis cannot be finalized before a therapist has actually made contact with another alter and observed the switch between alters.
The hallmark symptom is amnesia, which can be partial or complete depending on the level co-consciousness that exists between alters. Folks with the disorder describe the amnesia as "missing time" or blank periods, often daily or weekly, where they cannot account for their whereabouts or behavior. It is this amnesic barrier between parts that often leads to the most bizarre and distinctive signs and symptoms: not recognizing familiar people; not remembering highly significant events in their lives (like the birth of their first child, for example); finding purchases or articles of clothing/possessions, writings or drawings that they have no recollection of having bought or created. They are frequently accused of lying because they disavow their own behavior which is remembered by one part, while the amnestic part is completely unaware of it. Other unusual symptoms include: an exceptionally high tolerance for physical pain (they split off physical sensation which becomes encapsulated in one or several alters without others feeling it); not recognizing themselves in a mirror; using different names; having dramatically different skills and abilities that seem to be alternately present and then vanish (one alter may be able to drive a car while the sudden emergence of a child alter results in complete loss of this ability until the adult alter re-emerges); completely different opinions and behaviors (leading to the mislabeling of Bipolar or Borderline Personality.
Often communication across between separate alters takes place in the form of hearing voices, hence these folks frequently get misdiagnosed as schizophrenic. The key distinction here is whether the voices are experienced as coming from inside the person's head (DID) or outside one's head (Schizophrenia/Bipolar Disorder).
The separate identities develop in response to traumatic experiences which the child is unable to integrate and so they become "split off" from awareness and begin to take on a life of their own.
Folks with DID often self-injure, frequently a result of internal battles between persecutor alters and weaker alters and there are continual battles for control of the body and "time out" in the body between competing alters.
Symptoms of depression and anxiety are frequent and common and the picture is further complicated by the fact that one alter can meet all clinical criteria for Depression, while another part experiences no symptoms whatsoever. One part can be psychotic and experience no side effects from meds while another non-psychotic part has all the side effects and will stop taking meds. You can imagine that attempting to medicate such a disorder becomes an absolute nightmare.
Other symptoms include flashbacks and nightmares, hence the confusion with PTSD. Sometimes there are fugue states and clients will switch and "come to" in the body and have no idea how they arrived in the situation they are in, not know the people they are with and be completely disoriented. I had one client call me from another state after being away for a few days and having no idea how she got there or how to get home. Depersonalization and trance states are common and hence the overlap with other Dissociative disorders.
Folks with DID frequently experience multiple somatic symptoms for which there is no organic basis. They experience partial body memories of abuse without the actual memory of the event and thus exhibit strange physiological symptoms and are often labeled as Somatoform disorders or hypochondriacs.
I could go on and on, but suffice it to say that virtually any symptom of any disorder can be found at some point in a person with DID. Treatment is almost exclusively through psychotherapy as medication is merely palliative and an adjunct during periods of acute anxiety or depression. Treatment aims at initially contracting against suicidal and self-destructive behavior and attempts to establish safety first. Many DID folks enter treatment in horrendous circumstances where they are frequently in highly abusive relationships or are themselves abusive. Given the multiple alters, they may be both victim and perpetrator both within themselves alone and in the context of their relationships. The second primary goal is establishing communication and negotiation among alters to decrease amnesia and contradictory, self-defeating behavior. Ultimately the goal becomes integration of alters into one cohesive whole which involves sharing of memories and feelings across alters and a merging, where all parts continue to be present, but constant.