Legion deals with the mental illness schizophrenia.
Legion (Marvel Comics) . Legion takes the role of an antihero and has a severe mental illness including a form of dissociative identity disorder in which each of his alternate personas controls one of his many superpowers . Legion (TV series) . Dan Stevens stars as Haller , a mutant diagnosed with schizophrenia at a young age . Schizophrenia is a mental disorder characterized by abnormal social behavior and failure to understand what is real .