Can people die from schizophrenia? do they experience facial changes? body changes? other than their personality? are they one person or many?

The physical manifestations you mention could be perceived to be present if part of delusional material the patient experiences as real. Death from suicide is possible, monitoring by a health professional to look for any evidence of suicidal or homicidal ideation is an important part of care. Do not confuse with Dissociative Identity Disorder, where patients have alter egos